Trunk muscles strength as a risk factor for nonspecific low back pain: a pilot study

[Isokinetic strength testing with different biomechanical demands on core strength: a comparison of military competitive athletes and soldiers with high occupational physical strain]

It is known that anthropometric data (weight, height, BMI, waist circumference and WHtR) and male gender are positively correlated with greater core strength, while age is negatively correlated. For competitive athletes with no significant differences in the anthropometric data stated above, there have hardly been any studies in which isometric core strength in a seated position is quantitatively compared among athletes in different sports. This study aimed to analyse different sports in well-trained athletes using military competitive sports as an example with regard to possible differences in core strength. For this purpose, Parachuting (n=28), Military Pentathlon (n=34) and Ski Platoon (n=38) groups were compared with regard to isokinetic core strength using dynamometry in seated position. In addition to the comparison of anthropometry and isokinetic results with descriptive statistics, ANOVA and Welch-ANOVA were used to compare the means of absolute and weight-adjusted core strength. It was shown that the Ski Platoon group had significantly higher flexion peak torque values than the Military Pentathlon and Parachuting groups. Even when adjusted for weight, the values were significantly higher than those measured in the Military Pentathlon group but not significantly higher than those in the Parachuting group. For extension peak torque, it was found that the Military Pentathlon group had significantly lower values than the Ski Platoon group and, in the weight-adjusted analysis, significantly lower values than the Parachuters. Using the example of competitive military sports, this study was able to show that there are significant differences in isokinetic core strength even among professional competitive athletes.This knowledge should be used to carry out detailed quantitative analyses of core strength, even in well-trained professional athletes, to find applications for prevention or to coordinate compensating exercises.

The role of muscle function and pointe shoe characteristics in Arabesque movement among ballet dancers with non-specific low back pain

This study aimed to investigate posterior chain muscle function and the influence of pointe shoes in ballet dancers with and without low back pain (LBP) in the Arabesque. Twenty-nine young professional ballet dancers (17 with LBP and 12 healthy controls) were recruited. Muscle strength and mechanical properties of the erector spinae and hamstrings were assessed. The displacement of centre of mass (COM) during Arabesque under different shoe conditions (R-class, Chacott, and own shoes) was measured with a motion capture system. The LBP group exhibited greater dynamic stiffness and decreased mechanical stress relaxation time in the lateral hamstring compared to the control group. During Arabesque, the LBP group demonstrated significantly greater anterior-posterior displacement of the COM and a larger percentage of time to achieve maximal trunk extension angle. The COM displacement in vertical and medial-lateral directions was smaller in the R-class than in their own shoes. LBP impacts muscle mechanical properties, particularly in the lateral hamstring. The compromised muscle function resulted in a longer time to spinal extension during Arabesque, signifying that reduced trunk control contributed to greater COM displacement. Hence, it is essential to emphasise that evaluating muscle properties and dynamic postural control is imperative for dancers experiencing LBP.

Association of Muscle Strength, Psychological Factors, and Central Sensitization With Movement-Evoked Pain in Patients With Nonspecific Chronic Low Back Pain: The BACKFIT Project

BACKGROUND

People with chronic pain might evade certain movements to prevent their experience of pain. Movement-evoked pain (MEP) might induce lower functionality during daily activities.

HYPOTHESIS

(1) MEP after physical fitness tests would vary depending on the main musculature involved in the test; (2) physical and psychological factors would be associated with MEP in patients with NSCLBP.

STUDY DESIGN

Cross-sectional design.

LEVEL OF EVIDENCE

Level 3.

METHODS

A total of 104 (69 women) patients aged 51.0 ± 10.3 years with NSCLBP participated. MEP was measured with a visual analog scale (VAS) at baseline and immediately after performing each physical fitness test, that is, the Biering-Sørensen, prone bridging, handgrip, chair-stand, and 8-foot time-up-and-go tests, measuring back extensor, back flexor, upper- and lower-body muscle strength, and motor agility, respectively. Global muscle strength was calculated with normalized index (z-score) procedure. Depression, anxiety, pain catastrophizing, and central sensitization were assessed with the Beck Depression Inventory II, State Trait Anxiety Inventory I, Pain Catastrophizing Scale, and Central Sensitization Inventory (CSI), respectively.

RESULTS

Patients showed greater pain after completion of the Biering-Sørensen (mean difference 95% CI, 0.02, 1.11), prone bridging (0.15, 1.21), lower pain after handgrip (-1.46, -0.52), and the 8-foot time-up-and-go (-1.43, 0.46) tests (all P ≤ 0.04). Lower global muscular strength (β between -0.18 and -0.30), and greater pain catastrophizing (β = 0.16), and CSI scoring (β between 0.18 and 0.27) were associated with greater MEP (all P ≤ 0.04).

CONCLUSION

Greater MEP was observed after tests measuring core musculature strength than after tests measuring distal (limbs) strength and agility. Greater MEP was overall associated with lower muscle strength, greater pain catastrophizing, and central sensitization.

CLINICAL RELEVANCE

Fitness testing might be implemented as a complementary tool for the monitoring of NSCLBP in clinical settings.

Reliability of a Trunk Flexion and Extensor Muscle Strength Test with Hand-Held and Isokinetic Dynamometers in Female Athletes

An accurate trunk muscle strength assessment seems very important to design and individualize training and rehabilitation programs in clinical and sport settings. Hand-held dynamometers (HHDs) are interesting alternatives to isokinetic dynamometers for assessing trunk isometric muscle strength because they are inexpensive instruments and easy to use. This cross-sectional observational study aimed to examine the reliability of two novel sitting tests for assessing trunk flexion and extension isometric strength using an HHD and their relationship with two other novel isometric tests that use an isokinetic dynamometer. Twenty-four female amateur athletes (age: 24.5 ± 2.64 years; body height: 164.45 ± 6.33 cm; body mass: 63.17 ± 10.35 kg) participated in this study. A test-retest design was carried out one-week apart to examine the reliability. The relationship and the degree of agreement between the HHD and the isokinetic dynamometer measurements were analysed using Pearson correlation and Bland-Altman analysis, respectively. In general, the reliability of all isometric strength tests was good, with ICCs ranging from 0.65 to 0.87 and typical error < 15%. Pearson correlations were moderate, with values of r = 0.47 (R2 = 0.22) and r = 0.42 (R2 = 0.18) for flexion and extension strength, respectively. Bland-Altman plots showed no agreement between HHDs and isokinetic measurements. All trunk isometric tests using both, an isokinetic dynamometer and HHDs, provide reliable measurements for assessing trunk flexion and extension strength. According to the comparative analysis, both measurement types are different and cannot be used interchangeably. Health and sport professionals should choose the test that best suits the biomechanical characteristics required for functional goals or success in a given sport.

The MedXFit-study - CrossFit as a workplace health intervention: a one-year, prospective, controlled, longitudinal, intervention study

Introduction

Workplace health interventions aim to motivate employees toward healthy behaviors to improve fitness and health in the long-term. We investigated whether CrossFit® is an effective training concept to achieve these goals in inactive employees with sedentary occupations.

Methods

The study followed a prospective, controlled intervention design. Employees were invited to participate in intervention group (IG) or control group (CG) on their own preferences. Inclusion criteria were a predominantly sedentary occupation and execution of less than two muscle and/or mobility enhancing training sessions per week at the time of enrolling. The IG did at least two times a week a CrossFit training of 1 h. Mobility, strength, well-being, and back-issues were measured at the beginning, after 6, and 12 months. Participants in the CG were free to choose any other activities offered at the same time (e.g., circuit training, meditation, full body stability training). Adherence, respectively, behavioral change and maintenance qualities were evaluated based on the COM-B system and presence of behavior maintenance motives.

Results

89 employees were enrolled into the trial, from where 21 dropped out due to external factors (24%). From the remaining participants, 10 out of 39 (26%) in the IG and 1 out of 29 (4%) in the CG stopped for intrinsic reasons, leading to a non-adherence to the intervention of 22 percentage points. Motivation for behavioral change and maintenance in the IG was primarily driven by enhanced physical and psychological capability. Development of physical capability was evident by significant improvements (p < 0.001) in the IG compared to the CG for mobility (d = 3.3), maximal isometric strength (min. d = 1.7, max. d = 2.5), as well as reduction in pain intensity (p = 0.003, r = 0.4) and frequency (p = 0.009, r = 0.35) after 12 months. Significant improvements between the 6-month and the 12-month measurement in mobility and 6 out of 8 strength measures within the IG indicated the effectiveness of CrossFit beyond the beginner phase.

Conclusion

CrossFit is a motivating training concept that led to long-term health and fitness improvements in inactive employees doing sedentary work and should be given greater consideration in workplace health promotion.

Rehabilitation therapy using the HUBER platform in chronic non-specific low back pain: a randomized controlled trial

BACKGROUND

Non-specific chronic low back pain (NSCLBP) refers to a complex condition that involves structural, biomechanical, cognitive, psychological, social, and lifestyle issues. First-line therapies include physical therapy and exercise, as well as psychological follow-up and pain medication.

AIM

The aim of this study was to assess the impact of a 6-week center-based program using a multi-axis motorized platform (HUBER) connected with force sensors, that allows the patients to execute isometric exercises on the spine flexion-to-extension ratio at 60 and 120°/s, pain, trunk flexibility, and disability.

DESIGN

The design of the study was prospective, active control, parallel-group, assessor-blinded, randomized controlled trial.

SETTING

The setting was outpatients physical therapy clinic.

POPULATION

The population analyzed presented NSCLBP.

METHODS

Seventy individuals with NSCLBP were randomized into 2 intervention arms (1:1 ratio): 1/standard rehabilitation group (STAND) with physiotherapy, balneotherapy and cycloergometer exercises and 2/HUBER rehabilitation group (HUB) with physiotherapy, balneotherapy and HUBER exercises. Both programs lasted 6 weeks, with 4 sessions of 2 hours each per week.

RESULTS

Each group reported statistically significant improvements on the isokinetic spine strength, flexibility of the trunk, lumbar joint mobility, muscular endurance of the trunk and of the lower limbs, pain score and disability (P<0.05). The spine flexion/extension ratio at 60˚/s improved similarly between groups (-22.23 for HUB, and -13.04 for STAND; P=0.178) with a greater effect size in HUB. Only HUB reported a significant improvement in the spine flexion-to-extension ratio at 120˚/s (from 87.3 to 78.6, P=0.012). HUB reported a greater decrease in the Oswestry Disability Index (-16.83) compared to STAND (-12.11), with a statistically significant effect between groups (P=0.036).

CONCLUSIONS

Exercises performed on the HUBER platform added to physiotherapy and balneotherapy are as effective as a standard rehabilitation program with physiotherapy, balneotherapy and cycloergometer exercises to improve isokinetic spine strength, lumbar joint mobility, flexibility and muscular endurance of the trunk and the lower limbs. In addition, exercising with the HUBER platform result in a greater reduction in disability compared to a standard rehabilitation program (clinicalTrials.gov: NCT05437016).

CLINICAL REHABILITATION IMPACT

A variety of intervention techniques, including supervised exercise and manual therapy are now used to manage persistent NSCLBP. The added value of the HUBER device on disability suggests that the platform could be beneficial.

Effectiveness of Transcutaneous Neuromodulation on Abductor Muscles Electrical Activity in Subjects with Chronic Low Back Pain: A Randomized, Controlled, Crossover Clinical Trial

Introduction

Non-specific chronic low back pain (NSCLBP) is a major cause of functional impairment, resulting in consequences like job absenteeism and reduced quality of life. Risk factors such as muscle weakness and tightness have been implicated. Electromagnetic fields have therapeutic effects on human tissue, including pain relief and muscle relaxation. This study aimed to examine the impact of a tape with magnetic particles (MPT) applied to the lumbar area on abductor muscle strength and surface electromyography (sEMG) of the Gluteus Medius and Tensor of the Fascia Lata muscles in individuals with NSCLBP.

Methods

It was carried out a double-blind, randomized, controlled, crossover trial and with test retest, with 41 consecutive patients younger than 65 years who previously diagnosed with NSCLBP to assess the effect of a MPT over hip abductor muscle strength and activity. sEMG and force data were obtained during the Hip Stability Isometric Test (HipSIT). The HipSIT was used to assess the abduction strength using a hand-held dynamometer and sEMG. The HipSIT uses the maximum voluntary isometric contraction (MVIC). Four trials were recorded and the mean extracted for analysis. The tape was applied with either a MPT or a sham magnetic particle tape (SMPT) bilaterally without tension on from L1 to L5 paravertebral muscles.

Results

The significant increase in the recruitment of fibers and the significant increase in the maximum voluntary contraction by applying MPT with respect to the SMPT, correspond to the increases in the Peak Force and the decrease in the time to reach the maximum force (peak time) of both muscles.

Conclusion

Application of a MPT in patients with NSCLBP suggests an increase in muscle strength of the Gluteus Medius and Tensor Fascia Lata bilaterally during the HipSIT test. Lumbar metameric neuromodulation with MPT improves muscle activation of the hip musculature.

Effect of two suspension training programs on pain and musculoskeletal function in chronic low back pain: study protocol

The aim of this study is to compare the effects of two suspension training (ST) protocols on pain and musculoskeletal function in women with chronic low back pain (CLBP). The study will be randomized, controlled, blinded clinical trial. Women aged 18-60 years who present CLBP will be selected. They will be randomized into three groups: STG1, which will carry out the program with difficulty progression in the exercises; STG2, in which the progression will be made by increasing the number of sets; and control group. STG1 and STG2 will perform the training two-times a week for 60 min for 12 weeks. It is expected that ST will effectively reduce pain and improve functionality in CLBP and that the best protocol will be verified. Clinical Trial Registration: RBR-10rv3fqt.

Comparison of the Efficiency of Core Stabilization Exercises and Abdominal Corset in the Treatment of Postpartum Diastasis Recti Abdominis

OBJECTIVE

To examine the feasibility of three physiotherapy interventions for the treatment of diastasis recti abdominis (DRA): core stabilization exercises, abdominal corset and a combination of exercise and abdominal corset.

STUDY DESIGN

Forty-five women 6 to 12 weeks postpartum who were diagnosed with DRA by a gynecologist/obstetrician were recruited for the study. The women were randomly divided into three groups: core stabilization exercises (1st group), the combination of exercise and abdominal corset (2nd group) and abdominal corset (3rd group). The treatment session for each group continued for 8 weeks. Outcome measurements were pain evaluation, inter-rectus distance (IRD) measured using ultrasound, trunk flexion strength and endurance, balance with open eyes/closed with a balance board, and Oswestry Disability Index (ODI).

RESULTS

Statistically significant difference was observed in all outcome measures except the balance eyes closed results in the first group (p < 0.05). There was a statistically significant difference in all outcome measures in the second group (p < 0.05). Also, there was a statistically significant difference in visual analog scale, trunk flexor endurance, IRD results, balance with open eyes and ODI results in the third group (p < 0.05). When the values pre and post-treatment between the groups were examined, a statistically significant change was observed in trunk flexion strength, trunk flexor endurance, and balance with open eyes/closed parameters (p < 0.05).

CONCLUSIONS

Physiotherapy interventions as core stabilization exercises and the abdominal corset can positively impact IRD, trunk flexion muscle strength and endurance, balance and disability in DRA management. The combination of exercise and corset was found more effective in the postpartum process.

Prevalence and factors associated with low back pain in warehouse workers: A cross-sectional study

BACKGROUND

Low back pain is a highly prevalent musculoskeletal disorder that leads to functional incapacity and absence from work.

OBJECTIVE

To analyze warehouse workers' prevalence and factors associated with low back pain.

METHODS

Cross-sectional study design with 204 male warehouse workers (stocker, separator, checker, and packer) from motor parts companies. Age, body mass, marital status, education, the practice of physical exercise, presence of pain, low back pain intensity, comorbidities, time away from work, handgrip strength, flexibility, and trunk muscle strength were collected and analyzed. Data are presented as mean, standard deviation, absolute and relative frequency. A binary logistic regression was performed, with low back pain (yes or no) as the dependent variable.

RESULTS

24.0% of the workers reported low back pain with an average intensity of 4.7 (± 2.4) points. The participants were young, had completed high school education, were single and married, and had normal body weight. There was a more likely low back pain presence in separator tasks. Greater handgrip strength in the dominant (right) hand and trunk muscle is associated with no low back pain.

CONCLUSION

Low back pain prevalence was 24% among young warehouse workers, more likely in separation tasks. A greater handgrip and trunk strength can be a protective factor to no low back pain.

Effect of Trunk-Focused Exercises on Pain, Disability, Quality of Life, and Trunk Physical Fitness in Low Back Pain and How Potential Effect Modifiers Modulate Their Effects: A Systematic Review With Meta-analyses

OBJECTIVE: To analyze the effect of trunkfocused exercise programs (TEPs) and moderator factors on chronic nonspecific low back pain (LBP). DESIGN: Systematic review with meta-analyses. LITERATURE SEARCH: We searched the PubMed, Scopus, Embase, SPORTDiscus, and CENTRAL databases from their inception to June 2022. STUDY SELECTION CRITERIA: We included randomized controlled trials comparing TEPs to control or general exercises. DATA SYNTHESIS: We used random-effects models to calculate the standardized mean difference (SMD) plus confidence interval (CI) and heterogeneity (I²) for pain, disability, quality of life, and trunk performance. The impact of moderator factors was analyzed through meta-regression. RESULTS: Forty randomized controlled trials (n = 2391) were included. TEPs showed positive effects for all outcomes versus control (SMD 0.90-2.46; 95% CI, -0.04 to 4.96; I2 61%-98%). There were small effects in favor of TEPs versus general exercises for pain (SMD = 0.20; 95% CI, 0.03-0.37; I² = 13.4%) and disability (SMD = 0.20; 95% CI, 0.02-0.38; I² = 0%). Trunk and/or hip range-of-motion improvements were associated with greater reductions in pain (P<.01; β = 0.56; 95% CI, 0.25-0.87) and disability (P<.01; β = 0.66; 95% CI, 0.27-1.05). Low body mass was associated with higher pain reduction (P = .03; β = -0.17; 95% CI, -0.32 to -0.02). CONCLUSIONS: Trunk-focused exercise programs had positive effects on pain, disability, quality of life, and trunk performance compared to control groups, and on pain and disability compared to general exercises. Increasing trunk and/or hip range of motion was associated with greater pain and disability reduction, and lower body mass with higher pain reduction. J Orthop Sports Phys Ther 2023;53(2):64-93. Epub: 16 January 2023. doi:10.2519/jospt.2023.11091.

Effectiveness of Spinal Stabilization Exercises on Movement Performance in Adults with Chronic Low Back Pain

Introduction

Low back pain (LBP) is a musculoskeletal disorder that affects more than 80% of people in the United States at least once in their lifetime. LBP is one of the most common complaints prompting individuals to seek medical care. The purpose of this study was to determine the effects of spinal stabilization exercises (SSEs) on movement performance, pain intensity, and disability level in adults with chronic low back pain (CLBP).

Methods

Forty participants, 20 in each group, with CLBP were recruited and randomly allocated into one of two interventions: SSEs and general exercises (GEs). All participants received their assigned intervention under supervision one to two times per week for the first four weeks and then were asked to continue their program at home for another four weeks. Outcome measures were collected at baseline, two weeks, four weeks, and eight weeks, including the Functional Movement ScreenTM (FMSTM), Numeric Pain Rating Scale (NPRS), and Modified Oswestry Low Back Pain Disability Questionnaire (OSW) scores.

Results

There was a significant interaction for the FMSTM scores (p = 0.016), but not for the NPRS and OSW scores. Post hoc analysis showed significant between-group differences between baseline and four weeks (p = 0.005) and between baseline and eight weeks (p = 0.026) favor SSEs over GEs. Further, the results demonstrated that all participants, regardless of group, had significant improvements in movement performance, pain intensity, and disability level over time.

Conclusion

The results of the study favor SSEs over GEs in improving movement performance for individuals with CLBP, specifically after four weeks of the supervised SSE program.

Isokinetic trunk training on pain, disability, and strength in non-specific low back pain patients: A systematic review and meta-analysis

BACKGROUND

Low back pain is one of the leading causes of disability globally, with a high economic and social burden. A decrease or imbalance in trunk strength has been associated with the occurrence of low back pain and its severity. Trunk strength training is helpful in the treatment of Non-specific low back pain (NSLBP) patients. However, we do not know the effects of trunk isokinetic training (IKT) on pain intensity, disability, and trunk strength.

OBJECTIVE

This systematic review aimed to determine the effects of trunk IKT in NSLBP patients on pain intensity, disability, and trunk flexor and extensor isokinetic strength.

METHODS

We searched PubMed, Web of Science, Scopus, CENTRAL, and PEDro, from January 2001 until March 2021 and updated to November 2022. Randomized controlled trials (RCTs) that investigated the effect of IKT in adult participants with NSLBP on pain intensity, disability, or isokinetic trunk strength were included. Mean difference (MD) and 95% confidence intervals (95% CI) were calculated for pain. Bias was assessed using the Cochrane risk of bias (RoB) tool and evidence certainty via Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

Among 1750 retrieved articles, eight were included in this review. Meta-analysis comparing IKT (trunk isokinetic training, n= 134) with control groups (conventional exercises, n= 133) revealed that IKT decreases pain intensity (MD -1.50 (95% CI: -2.60; -0.39)) immediately post-intervention, and one month (MD -1.97 (95% CI: -2.92; -1.03)) and at six months follow-up (MD -2.48 (95% CI: -2.77; -2.19)), although with a very low to low quality according to the GRADE rating. Besides, IKT decreases disability and increases isokinetic trunk strength, but with scant evidence.

CONCLUSIONS

Trunk IKT could be a novel clinical tool for pain management in patients with NSLBP, although evidence is scarce. In addition, few RCTs exist for IKT on disability or trunk isokinetic strength in patients with NSLBP. Therefore, further research on this topic is needed.

Investigation of the relationship between the clinical evaluation results of lumbar region muscles with cross-sectional area and fat infiltration

BACKGROUND

The relationship between the endurance of the lumbar paraspinal muscles and morphological changes needs to be clarified. In this context, the importance can be revealed of increasing the endurance level of the paraspinal muscles in the prevention and treatment of low back diseases.

OBJECTIVE

The aim of this study was to examine the relationship between the clinical evaluation results of the cross-sectional area (CSA) and fat infiltration of the lumbar deep paraspinal muscles.

METHODS

The study included 37 patients with mechanical low back pain (mechanical), 41 patients with lumbar hernia without root compression (discopathy) and 36 healthy individuals as a control group. The functional status of the lumbar deep paraspinal muscles was evaluated clinically with muscle endurance tests. The fat infiltration and CSA of the muscles were evaluated on axial MRI sections at the L3-S1 level.

RESULTS

The mean values of the prone bridge, Biering-Sorenson, and trunk flexion tests were seen to be highest in the control group and lowest in the discopathy group (p< 0.001). In all tests, the longest test period was obtained at < 10% fat infiltration and the shortest at > 50% fat infiltration. It was observed that as the amount of fat infiltration of the muscles increased, the test times were shortened. There was no significant relationship between the endurance level and the CSA of the groups.

CONCLUSION

The study results demonstrated that the endurance of the paraspinal muscles is associated with the fat infiltration of the muscles. In patients with chronic low back pain, information about muscle morphology and degeneration can be obtained with simple endurance tests without the need for further measurements. On clinical examination, a weak endurance level of the paraspinal muscles indicates the presence of a low back problem and an increase in the amount of fat infiltration.

The deer play in Wuqinxi and four-point hand−knee kneeling positions for training core muscle function and spinal mobility

The four-point kneeling exercise is a core stabilization exercise that provides the spine with dynamic stability and neuromuscular control. In the traditional Chinese exercise Wuqinxi, deer play is performed in a hand−foot kneeling (HFK) position, which is remarkably similar to the four-point hand−knee kneeling (HKK) position. However, the differences in spinal function promotion between these two positions are poorly understood. The aim of this study was to investigate muscle activation patterns and spinal kinematics during specific core stabilization training to provide evidence for selecting specific exercises. A total of 19 healthy adults were recruited to perform HFK and HKK. The rotation angle of the C7–T4 vertebra and the surface EMG signals of abdominal and lumbar muscles on both sides were collected. The paired t-test showed that the vertebral rotation angles were significantly higher during HKK than HFK, and the intra-group differences mainly occurred at the level of the thoracic vertebra. The muscle activation of both sides of the rectus abdominis and external oblique in HFK was significantly higher than in HKK when the upper limb was lifted (p < 0.05). The activation of the ipsilateral lumbar multifidus and erector spinae muscles was significantly higher during the HKK position than during HFK when the lower limb was lifted (p < 0.05). HFK provided more training for strengthening abdominal muscles, while HKK could be recommended for strengthening lumbar muscles and increasing spine mobility. These findings can be used to help physiotherapists, fitness coaches, and others to select specific core exercises and develop individualized training programs.

Reliability of trunk strength measurements with an isokinetic dynamometer in non-specific low back pain patients: A systematic review

BACKGROUND

Imbalance or decreased trunk strength has been associated with non-specific low back pain (NSLBP).

OBJECTIVE

This systematic review aimed (I) to evaluate the quality of evidence of studies evaluating the reliability of trunk strength assessment with an isokinetic dynamometer in NSLBP patients, (II) to examine the reliability of trunk strength assessment using an isokinetic dynamometer in NSLBP patients and (III) to determine the most reliable protocol for trunk strength assessment in NSLBP patients.

METHOD

PRISMA guidelines were followed. Three databases were used: PubMed, Scopus, and Web of Science with the following keywords: Isokinetic, Dynamometer, Trunk strength testing, Muscle testing, Isokinetic measurement, CORE, Abdominal muscles, Abdominal wall, Torso, Trunk, Spine, Reliability and, Reproducibility. We included only test-retest studies, focused on the reliability of isometric and isokinetic strength assessed with an isokinetic dynamometer in NSLBP adults' patients, published in English and from inception to March 30, 2021. The methodological quality was evaluated with the CAT scale and QAREL checklist.

RESULTS

Five hundred and seventy-seven articles were retrieved, of which five are included in this review. Three articles provide good quality of evidence, the reliability of trunk strength assessment in NSLBP patients is excellent, and the most reliable protocol for isometric assessment is in a seated position (ICC = 0.94-0.98) and for isokinetic strength in standing position, at 60∘/s and 120∘/s (ICC = 0.98).

CONCLUSION

There is good quality evidence regarding the trunk strength assessment's reliability. Reliability is excellent in NSLBP patients; however, a familiarization process should be considered to obtain clinically reliable data. The most reliable protocol is in a seated position for isometric strength and a standing position for isokinetic strength.

Surface Electromyographic Activity of the Rectus Abdominis and External Oblique during Isometric and Dynamic Exercises

Exercises for the abdominal muscles are widely used in athletic activities for strength training and prevention of low back disorders. The timing and volume of muscle activation for various movements have not yet been clarified. The purpose of this research was to evaluate the surface electromyographic activity from the upper (RAU) and lower part (RAL) of the rectus abdominis and the external oblique (EO) muscles during eleven abdominal muscle strength training exercises. Thirty-five healthy male university students with a subspecialty in soccer participated in the study. They performed exercises involving isometric, concentric, and eccentric muscle contractions. The electromyographic recordings were amplified by a factor of 1000, rectified, and integrated. Mean integrated values were calculated by dividing the elapsed time for the five repetitions, to provide the mean integrated electromyographic values for each exercise. Leg movements from a long lying position showed higher activity of the rectus abdominis, compared to the EO (p < 0.001). The dynamic sit-ups showed an obvious dominant activity of the EO, compared to the rectus abdominis (p < 0.001). During eccentric exercise, higher activity was found in the RAU, compared to the RAL (p < 0.001). The results could serve as a basis for improving the design and specification of training exercises. Pre-exercises should be performed before testing abdominal muscle strength.

The Japan Frailty Scale is a promising screening test for frailty and pre-frailty in Japanese elderly people

Frailty is one of the most important problems in a super-aged society. It is necessary to identify frailty quickly and easily at the bedside. We developed a simple patient-reported frailty screening scale, the Japan Frailty Scale (JFS), based on the aging concept of Kampo medicine. Eight candidate questions were prepared by Kampo medicine experts, and a simple prediction model was created in the development cohort (n=434) and externally validated in an independent validation cohort (n=276). The physical indicators and questionnaires associated with frailty were also comprehensively evaluated. The reference standard for frailty or pre-frailty was determined based on the Kihon checklist. In the development cohort, four questions, nocturia (0-2), lumbago (0-2), cold sensitivity (0-2), exhaustion (0-4), and age (0-1) were selected by multivariable logistic regression analysis. The total JFS score is 0-11. Receiver-operating characteristic curve analysis of the JFS for identifying frailty status showed moderately good discrimination (area under the curve (AUC) =0.78, 95% confidence interval (CI): 0.73-0.82). At the JFS cutoff value of 3/4 for frailty or pre-frailty, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 86.9%, 53.3%, 62.8%, and 81.7%, respectively. External validation of the JFS showed moderately good discrimination (AUC=0.76, 95% CI: 0.70-0.81). The sensitivity, specificity, PPV, and NPV were 79.9%, 61.4%, 69.3%, and 73.7%, respectively. These results indicate that the JFS is a promising patient-reported clinical scale for early identification of pre-frail/frail patients at the bedside in primary care.

Effects of an Intensive 6-Week Rehabilitation Program with the HUBER Platform in the Treatment of Non-Specific Chronic Low Back Pain: A Pilot Study

Non-specific chronic low back pain (NSCLBP) is defined as a complex disorder involving structural, biomechanical, cognitive, psychological, social, and lifestyle factors. Non-pharmacological approaches such as exercise and physical therapy have been proposed in first-line treatments, along with psychological follow-up and pain medication if needed. Our objective was to evaluate the effectiveness of an intensive rehabilitation program with HUBER (a multi-axis motorized platform equipped with force sensors, allowing patients to perform physical exercises in an isometric mode) on the spine flexion-to-extension ratio at 60 and 120°/s, pain, and trunk flexibility in individuals with NSCLBP. Twelve participants underwent a clinical evaluation including isokinetic spine strength and participated in a 6-week rehabilitation program with HUBER 360 Evolution. The main findings of this pilot study show that the flexor/extensor ratios at 60°, the flexibility of the hamstring and quadriceps, and muscular endurance of the trunk, disability, and quality of life were significantly improved at the end of the rehabilitation program (p < 0.05). Low back pain and analgesic medication were also reduced. Exercising with the HUBER Platform seems to be effective in managing NSCLBP but a randomized study with a larger sample size and a control group is necessary.

Practicable performance-based outcome measures of trunk muscle strength and their measurement properties: A systematic review and narrative synthesis

Introduction

The evaluation of muscle strength is frequently used as part of the physical examination process, with decreased trunk muscle strength reported in individuals with spinal disorders (e.g., low back pain). Access to practicable performance-based outcome measures (PBOM) to monitor patients’ progress in spinal rehabilitation is essential. Knowledge of the psychometric properties of the available practicable PBOM for trunk strength evaluation is therefore needed to inform practitioners and further research.

Objective

To synthesise evidence on the measurement properties of practicable measures of trunk muscle strength in adults with and without musculoskeletal pain.

Methods

Following a published and registered protocol [PROSPERO CRD42020167464], databases were searched from the database inception date up to 30th of June 2021. Citations and grey literature were also searched. Eligibility criteria comprised: 1) studies which examined the psychometric properties of the trunk strength outcome measures, 2) included adults ≥ 18 years, either asymptomatic or with spinal musculoskeletal pain. Non-English language studies were excluded. Two independent reviewers evaluated the quality and synthesized the data from included studies according to the COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) checklist. The overall quality of evidence was evaluated using a modified Grading of Recommendations Assessment Development and Evaluation (GRADE).

Results

From 34 included studies, 15 different PBOMs were identified that have been investigated for reliability and validity, none evaluated responsiveness. In asymptomatic individuals, high quality evidence supports intra-rater reliability of digital-loading cells and moderate quality evidence supports the criterion validity of the hand-held dynamometer. Very low quality evidence exists for the reliability and validity estimates of testing tools among individuals with spinal pain.

Conclusions

Findings underpin a cautious recommendation for the use of practicable PROMs to evaluate muscle strength in individuals with spinal pain in clinical practice due to the level of evidence and the heterogeneity of the protocols used. Further high quality research to explore the psychometric properties of the practicable PBOMs with detailed methodology is now needed.

Variações baseadas em gênero no movimento e na força isométrica do tronco em jovens adultos com dor lombar: Um estudo de caso-controle prospectivo

Objective  To determine gender-based variations in trunk range of motion (RoM) and isometric strength (IS) in symptomatic and asymptomatic young adults.

Methods  In this prospective case-control study, 73 subjects with low back pain (LBP) and 80 asymptomatic subjects were analyzed. Dynamometer-based device trunk RoM and IS measurements in extension, flexion, and rotation were compared in both groups and gender-based subgroups. Multivariate analysis was used to determine factors influencing trunk RoM and IS.

Results  Symptomatic males had significantly less extension RoM and extension, flexion, and rotation isometric trunk strength (ITS) ( p  < 0.0001) compared with asymptomatic males, whereas no significant difference was found between asymptomatic and symptomatic females. However, the mean extension-flexion RoM and mean extension-flexion ITS ratios were significantly lower ( p  = 0.04) in asymptomatic females compared with symptomatic females. Female gender was significantly associated with less extension and flexion ITS in both asymptomatic and symptomatic subjects.

Conclusion  Males with LBP had significant global ITS weakness when compared with asymptomatic males. Despite no significant ITS difference in symptomatic versus asymptomatic females, LBP caused significant extension-flexion RoM and ITS imbalance in females. These gender-based variations in trunk RoM and IS, especially the extensor-flexor IS imbalance in females, must be considered while designing rehabilitation treatment protocols for LBP.

The influence of hip flexion mobility and lumbar spine extensor strength on lumbar spine flexion during a squat lift

STUDY DESIGN

Cross-sectional; Controlled laboratory study.

OBJECTIVE

To examine the associations among available hip flexion motion, lumbar extensor strength and peak lumbar flexion during a squat lift task.

SUMMARY OF BACKGROUND DATA

Lumbar spine flexion during lifting can result in increased strain on spinal structures. Although decreased available hip flexion motion and reduced strength of the lumbar extensor muscles has been proposed to contribute to greater lumbar flexion during lifting, direct relationships have not been explored.

METHODS

Fifty healthy young adults participated (23 males and 27 females). Strength of the lumbar extensors was measured using a motor-driven dynamometer. Available hip flexion was assessed using 3D motion capture. Peak lumbar spine flexion and hip flexion were quantified during the descent phase of the squat lifting task.

RESULTS

There was a significant negative association between available hip flexion and peak lumbar spine flexion during squat lifting in females (r = -0.407, p = 0.035) but not males (r = -0.341, p = 0.120). Similarly, peak lumbar spine flexion was negatively associated with lumbar extensor strength in females (r = -0.398, p = 0.040) but not males (r = -0.310, p = 0.161). During the squat lift, peak hip motion was positively associated with available hip flexion for both males and females combined (r = 0.774, p < 0.001).

CONCLUSION

Females with less available hip flexion and lower lumbar extensor strength exhibit greater lumbar flexion when performing a lifting task. Clinicians should be aware of the potential contributions of such impairments when instructing patients into various lifting strategies.

Effects of Core Stabilization Exercise Programs on Changes in Erector Spinae Contractile Properties and Isokinetic Muscle Function of Adult Females with a Sedentary Lifestyle

This study aimed to investigate the effect of core stabilization exercises on the contractile properties and isokinetic muscle function of adult females with a sedentary lifestyle. We enrolled 105 adult females. Tensiomyography was performed on the erector spinae, and the isokinetic muscular functional test was performed on the trunk at an angular velocity of 60°/s and 90°/s. All participants performed the exercise for 60 min per day, 3 times a week, for 7 weeks. A Wilcoxon signed-rank test was performed at a significance level of 0.05. Tensiomyography (TMG) of the erector spinae revealed no significant post-exercise change in the contraction time; however, there was a significant post-exercise increase in the maximum radial displacement and mean velocity until 90% of the TMG was displaced. Additionally, the isokinetic muscular functional test of the trunk revealed a significant post-exercise increase in almost all variables. Our findings demonstrated that the core stabilization exercise reduced stiffness in the erector spinae, increased the velocity of erector spinae contraction, and effectively improved the isokinetic muscular function of the trunk.

Association between Dietary Protein Intake, Regular Exercise, and Low Back Pain among Middle-Aged and Older Korean Adults without Osteoarthritis of the Lumbar Spine

This study aimed to evaluate the effect of dietary protein intake and regular exercise on low back pain (LBP) using data from the Korea National Health and Nutrition Examination Survey. A total of 2367 middle-aged and older adults (≥50 years) who underwent dual-energy X-ray absorptiometry and plain radiography of the lumbar spine were included. LBP was defined using a questionnaire to determine the presence of LBP lasting more than 30 days in the preceding three months. Twenty-four-hour dietary recall data were used to estimate protein intake, and regular exercise was assessed using the International Physical Activity Questionnaire. Multivariable logistic regression analysis revealed that men who did not perform regular exercise had a high probability of LBP (odds ratio [OR] 2.34; 95% confidence interval [CI] 1.24−4.44). Low protein intake (<0.8 g/kg/day) was associated with high odds for LBP in women (OR 1.83; 95% CI 1.12−2.99). Low protein intake and lack of regular exercise were also associated with a higher probability of LBP in women (OR 2.91; 95% CI 1.48−5.72). We recommend that women over 50 years of age consume the recommended daily amount of protein to prevent LBP and engage in regular exercise.

Chronic low back pain is associated with impaired bed turning ability: Evaluation by a mobility detection system

BACKGROUND

We aimed to assess and compare kinetics and kinematic variables of bed turning ability using a mobility detection system in patients with and without chronic low back pain and to observe the impacts of the disease on bed turning kinetics and kinematics.

METHODS

Thirty-five patients with chronic low back pain were enrolled and compared to healthy controls (n = 34). Pain scores and disability level were assessed by Numeric Pain Rating Scale and the function questionnaires including Oswestry Disability Index and Roland Morris Disability Questionnaire. Bed turning ability was tested using the Mobile Detection System. Univariate and multivariate regression analysis were applied to compare the differences between groups.

FINDINGS

Patients with chronic low back pain had significantly lower turning over and back force/weight ratio (p < 0.001) than those healthy controls. Turning over time was significantly longer in patients with Numeric Rating Scale score 3 than in those with Numeric Rating Scale score 2 (p = 0.015). Turning over and back force were significantly higher in male patients and patients with higher BMI after adjusting BMI and sex, respectively (all p < 0.001). When turning back, chronic low back pain patients with Numeric Rating Scale scores of 3 had lower turning back force/weight ratio than those with Numeric Rating Scale scores of 2 (p = 0.014). Male patients had higher turning back force/weight ratio after adjusting pain score (p = 0.001).

INTERPRETATION

The novel Mobility Detection System can provide more objective assessments of bed turning kinetics and kinematics in patients with chronic low back pain.

The effects of proprioceptive neuromuscular facilitation in treating chronic low back pain: A systematic review and meta-analysis

BACKGROUND

Proprioceptive neuromuscular facilitation (PNF) has been widely used in the clinical treatment of chronic low back pain (LBP) in recent years. However, its role remains controversial and it is unclear whether PNF offers more advantages for patients with chronic LBP.

OBJECTIVE

The purpose of this systematic review is to evaluate the evidence on the effect of PNF on pain, waist function, pulmonary function and dynamic balance in patients with chronic LBP.

METHODS

Seven English and Chinese electronic databases were searched to identify articles published from 1970 to February 2020. Relevant randomized controlled trials (RCTs) were selected by two independent reviewers to investigate PNF in treatment of chronic LBP. Data extraction was performed by the same reviewers.

RESULTS

Twelve eligible trials involving 410 participants were included in this meta-analysis. Compared with the control group, the aggregated results suggested that PNF showed beneficial effects in relieving pain (SMD =-1.17; 95% CI: -1.50 to -0.84; p< 0.00001) and improving waist functional disability (MD =-1.63; 95% CI: -1.89 to -1.37; p< 0.00001). In addition, PNF was shown to have a significant effect on pulmonary function (MD = 0.65; 95% CI: 0.26 to 1.03; p= 0.001). However, the results of the study show that PNF could not significantly improve dynamic balance in patients with chronic LBP compared with the control group (MD =-0.04; 95% CI: -2.16 to 2.08; p= 0.97). A high risk of bias occurred in the areas of blinding (i.e., participants/personnel and outcome assessment).

CONCLUSIONS

PNF showed more beneficial effects in pain relief and waist function improvement in patients with chronic LBP in the short term (4 to 8 weeks of intervention) or at 12-week follow-up and also played a positive role in pulmonary function. However, no significant effect of PNF on dynamic balance was found compared with the control group. However, these results have certain limitations, and these conclusions were supported by low-quality data. Therefore, articles that are methodologically reasonable and more authoritative are required to verify the effects. In addition, articles with long-term follow-up and other outcomes are needed to confirm additional findings.

Is the novel suspension exercises superior to core stability exercises on some EMG coordinates, pain and range of motion of patients with disk herniation?

Information about comparing the effectiveness of exercise methods on management of disk herniation is limited. The aim of this study was to compare the effect of two programs of suspension and core stability exercises on some electromyography (EMG) coordinates, pain and range of motion of patients with disk herniation. Thirty-two men with disk herniation participated in this clinical trial study which was randomly divided into three groups of suspension exercises (n: 12, age: 34.25 ± 8.81, BMI: 24.01 ± 2.7), core stability exercises (n: 10, age: 35 ± 10.3, BMI: 25 ± 2.27) and control (n: 10, age: 34.4 ± 6.67, BMI: 23.76 ± 1.45). Electrical activity of rectus abdominis, internal and external oblique and erector spinae muscles was masured by superficial EMG, back pain by McGill Pain Questionnaire and range of motion by Modified Schober test, one day before and immediately after of intervention period. The experimental groups performed an 8-week training period while the control group was only followed up. Data were analyzed using paired sample t test and analysis of covariance test and statistical significance was set at 0.05. Suspension group showed significant improvement in EMG of rectus abdominis, internal and external oblique muscles (respectively, p = 0.030, p = 0.017, p = 0.022) and pain (p = 0.001) compared to core stability group; but there was no significant difference between two groups in EMG of erector spinae muscle and range of motion. Changes in both training groups were significant in all variables compared to control groups (p ˂ 0.05). Our findings showed that although both exercises were effective in patients with lumbar disk herniation, but the effectiveness of suspension exercises in increasing muscle activation and reducing pain was more pronounced than core stability exercises.

Iranian Registry of Clinical Trials (IRCT): IRCT20191016045136N1.

Association between Relative Handgrip Strength and Chronic Lower Back Pain: A Nationwide Cross-Sectional Analysis of the Korea National Health and Nutrition Examination Survey

Lower back pain (LBP) is the most common musculoskeletal complaint and significantly reduces the quality of life. Muscle weakness is a major cause of LBP. Handgrip strength (HGS) is widely used to determine general muscle strength. Relative HGS (RHGS) incorporates body mass and provides a more accurate estimation of muscle strength and health status. We analyzed the data from Korea National Health and Nutrition Examination Survey to investigate the association between RHGS and chronic LBP. We identified 14,930 participants and excluded a total of 9553 participants with age < 50 years, with incomplete LBP information, and with incomplete HGS information. We analyzed the data of 5377 participants: 1086 (20.19%) with chronic LBP and 4291 (79.8%) without chronic LBP. Multivariate regression analysis with adjustment for covariates identified an association between weak RHGS and chronic LBP (odds ratio 1.31; CI 1.07-1.61; p = 0.01). This article demonstrated a significant association between RHGS and chronic LBP. Therefore, RHGS should be measured for patients with chronic LBP.

Isometric Trunk Strength Assessment of Athletes: Effects of Sex, Sport, and Low Back Pain History

CONTEXT

The importance of isometric trunk strength (ITS) among sport science professionals is higher than its actual reported effect size on either performance or low back pain (LBP) occurrence.

OBJECTIVE

To provide normative values of ITS and strength ratios, and to evaluate the effect of sex, sports discipline, and LBP status.

DESIGN

Crossover study.

SETTING

University research laboratory.

PARTICIPANTS

Five hundred and sixty-seven elite athletes (186 females) with and without a history of LBP from different sports.

MAIN OUTCOME MEASURE

Participants underwent ITS testing for trunk flexors, extensors, and lateral flexors. Normalized maximal strength (in newton meter per kilogram) and strength ratios were calculated. Differences between sex, LBP, and sport disciplines were assessed with 3-way analysis of variance (sex × LBP status × 7 sport categories) and partial eta-squared (ηp2) effect size. The predictive validity of ITS for LBP was checked with receiver operating characteristics (area under the curve).

RESULTS

The authors found significant differences in extensor and flexor ITS in favor of male athletes (medium ηp2, P < .05), while sex differences in lateral flexion ITS had a low size effect (P < .05). A low size effect was also observed for the differences in strength ratios extensors/flexors (mean 1.47; 95% confidence interval, 1.45-1.50) and left flexors/right flexors (mean 0.99; 95% confidence interval, 0.98-1.01) among sexes. The sport discipline-related differences generally had a low size effect. No significant differences in ITS were found between LBP and LBP-free athletes. Only 50% to 58% of athletes (area under the curve, 0.501-0.582) were correctly classified as LBP or LBP-free using different ITS and strength ratio variables.

CONCLUSIONS

ITS and strength ratios have low predictive validity for LBP history but may discriminate between sex and sport disciplines. Our data are a useful reference point for meaningful individual results interpretation when athletes are evaluated during training or rehabilitation.

Non-pharmacological Home Therapies for Subacute Low Back Pain in Active Duty Military Personnel: A Randomized Controlled Trial

INTRODUCTION

Low back pain (LBP) is a major cause of visits to ambulatory care, missed duty time, and disability discharge. The subacute phase of LBP presents an opportune time to prevent chronicity and lessen recurrence. The goal of this randomized controlled trial (RCT) was to determine the relative effectiveness of neuromuscular electrical stimulation (NMES) training and a progressive exercise program (PEP) on improving physical performance, pain, and torso strength in U.S. service members with subacute LBP, compared to standard primary care management (PCM) alone.

METHODS

This is an Institutional Review Board-approved protocol for an RCT conducted with active duty military personnel (n = 128) at Fort Campbell, Kentucky, between April 2018 and March 2020. Participants were randomized to receive NMES (n = 43), PEP (n = 42), or PCM (n = 43) for 9 weeks. Outcome measures of physical performance (sit-ups, push-ups, walking, and torso endurance), torso muscle strength (flexion and extension), and pain were assessed at baseline and after 3, 6, and 9 weeks. Analysis was intent-to-treat using linear mixed effects models. A sensitivity analysis was performed to address the protocol deviations that occurred in response to coronavirus disease 2019 pandemic, which required rescheduling 17 in-person study visits to home assessments at 9-week testing.

RESULTS

Evidence was found for group differences in physical performance for sit-ups and push-ups, with NMES showing greater improvement than PCM. The two groups showed similar improvements in torso muscle strength, although the NMES groups may show better improvement during early treatment. No group differences in pain levels were observed during the intervention, and all groups improved during the course of the study period. The amount of NMES muscle stimulation was directly related to the level of improvement, which was not the case for the hours reported for PEP exercise.

CONCLUSION

In an active duty population with subacute LBP, integrating NMES strength training into the rehabilitation therapy may offer a modest benefit for increasing sit-ups and push-ups and improving torso strength.

Exercise interventions can improve muscle strength, endurance, and electrical activity of lumbar extensors in individuals with non-specific low back pain: a systematic review with meta-analysis

Exercise interventions have been recommended for people with non-specific low back pain. The literature is scarce regarding the effects of exercise on muscle strength, endurance, and electrical activity of lumbar extensor muscles. Electronic searches were carried out from May 2020 until August 2020 in the following databases: PUBMED, CENTRAL, EMBASE, PEDro, SPORTDiscus, Scielo, and LILACS. Only randomized controlled trials with passive and active control groups were included. The methodological quality of the included studies was performed using the Physiotherapy Evidence Database Scale. Eight studies, involving 508 participants, were included in metanalytical procedures. Exercise interventions demonstrated superior effects on muscle activity (Electromyography) when compared with active controls (p < 0.0001). Exercise interventions demonstrated superior effects on muscle endurance (Sorensen Test) when compared with passive (p = 0.0340) and active controls (p = 0.0276). Exercise interventions demonstrated superior effects on muscle strength (Machine) when compared with passive controls (p = 0.0092). Exercise interventions can improve muscle strength, endurance, and electrical activity in people with non-specific low back pain.

The Potential Role of Hamstring Extensibility on Sagittal Pelvic Tilt, Sagittal Spinal Curves and Recurrent Low Back Pain in Team Sports Players: A Gender Perspective Analysis

It is assumed that mechanical restriction of hamstring tightness disrupts sagittal spine–pelvis–leg alignment and alters the lumbar–pelvic rhythm predisposing to low back pain (LBP) in athletes; however, this association is not clear. A prospective cross-sectional cohort study was conducted to determine the influence of hamstring extensibility (HE) on sagittal pelvic tilt, sagittal spinal curves, and LBP in 94 soccer and basketball players (61 man and 33 woman) with (n = 36) and without recurrent LBP (n = 58). Descriptive analysis displayed significant gender differences for HE, sagittal pelvic tilt, and lumbar curve. Differences were found between the low-HE and high-HE groups in lumbosacral angle in for the maximum trunk forward flexion (LH-MTFP). Low-HE was associated with LH-MTFP, lumbar curve and LBP in male players (p ≤ 0.023). In female players, LH-MTFP and lumbar curve were associated with low-HE (p ≤ 0.020). Low-HE predicted LH-MTFP (p = 0.000; OR = 65.6950) and LBP (p = 0.028; OR = 13.915) in male players. The decision tree analysis showed that 50.8% of the players were classified with restricted LH-MTFP, 77.4% with low-HE among male players. The 100% of male players with recurrent LBP had low-HE. The 65% of female players with low-HE had restricted LH-MTFP. Measurement of HE, lumbar curve, and LH-MTFP are important in making training decisions for to reduce the incidence of recurrent LBP in soccer and basketball players.

Normative Reference Values for Trunk Range of Motion and Isometric Muscle Strength in Asymptomatic Young Indian Adults

PURPOSE

To determine normative reference values for trunk range of motion (ROM) and isometric strength (TIS) in asymptomatic young, Indian adults.

METHODS

Age, gender, body mass index, lifestyle, and dynamometer-based device measurements of trunk ROM and TIS in extension (EXT), flexion (FLX), and rotation (ROT) were recorded and analysed in 80 asymptomatic subjects between 20 and 40 years of age. Correlation analysis was performed to determine factors influencing EXT and FLX ROM and TIS.

RESULTS

The normative reference values for mean trunk EXT, FLX, right ROT, and left ROT ROM were 23° (95th percentile 31.9°), 40.2°(95th percentile 51.5°), 36.8°(95th percentile 57.7°), and 35.4° (95th percentile 55.7°), respectively; and for mean EXT, FLX, right ROT, and left ROT TIS were 118.1 Nm (95th percentile 278.8 Nm), 63.8 Nm (95th percentile 159.4 Nm), 39.9 Nm (95th percentile 113.6 Nm), and 42.8 Nm (95th percentile 108.9 Nm), respectively. The mean EXT (p = 0.0002), right (p = 0.02), and left ROT ROM (p = 0.01), and the mean EXT, FLX, and ROT TIS (p < 0.0001) were significantly greater in males compared to females. The FLX, EXT, and ROT TIS showed significant strong correlation with EXT and FLX TIS. Mean TIS values in Indian subjects were lower when compared to subjects from other countries.

CONCLUSION

This study established normative reference values for trunk ROM and TIS in asymptomatic young Indian adults. These reference values can be helpful to diagnose trunk ROM and TIS deficits, identify subjects at risk for LBP and disability, and individualise rehabilitation treatment in them.

Altered Physical Performance Following Advanced Special Operations Tactical Training

ABSTRACT

Winters, JD, Heebner, NR, Johnson, AK, Poploski, KM, Royer, SD, Nagai, T, Randall, CA, Abt, JP, and Lephart, SM. Altered physical performance following advanced special operations tactical training. J Strength Cond Res 35(7): 1809-1816, 2021-The purpose of this study was to determine how the unique challenges of specific military tactical training phases influence overall physical performance characteristics. Broad jump, 5-10-5, 300-yd shuttle, percent body fat (%BF), anaerobic power (AP) and anaerobic capacity (AC), maximal oxygen uptake (V̇o2max), isokinetic knee extension/flexion strength, shoulder internal/external rotation strength, and trunk extension/flexion strength were collected on 73 United States Marine Corps Forces Special Operations Command (MARSOC) students (age: 27.4 ± 3.8 years, height: 178.7 ± 6.6 cm, and body mass: 85.8 ± 9.4 kg) at the beginning of (P1), in between (P2), and at the completion of 2 distinct tactical training phases (P3). Linear mixed models were used to analyze within-subject performance changes over the 3 time points, and post hoc Bonferroni pairwise comparisons analyzed performance changes between each testing time point. There were significant changes in broad jump (p < 0.0001), 5-10-5 agility time (p < 0.001), %BF (p = 0.011), AP (p < 0.0001), V̇o2max (p = 0.001), and both right and left shoulder internal rotation strength (p = 0.004 and p = 0.015, respectively) between P1 and P2. There were also significant changes in 300-yd shuttle run time (p = 0.001), AP (p < 0.0001), AC (p < 0.0001), left knee extension strength (p = 0.006), trunk flexion strength (p < 0.0001), and left shoulder external rotation strength (0.027) between P2 and P3. Identifying the effect that specific tactical training phases may have on physical performance will allow for the development of effective phase-specific evidence-based human performance programs, reducing performance deficits and thereby reducing the risk of injury.

Age-Related Changes in Concentric and Eccentric Isokinetic Peak Torque of the Trunk Muscles in Healthy Older Versus Younger Men

This study investigated age-related changes in trunk muscle function in healthy men and the moderating effect of physical activity. Twelve older (67.3 ± 6.0 years) and 12 younger (24.7 ± 3.1 years) men performed isokinetic trunk flexion and extension tests across a range of angular velocities (15°/s-180°/s) and contractile modes (concentric and eccentric). For concentric trunk extension, mixed-effects analysis of covariance revealed a significant interaction between Angular velocity × Age group (p = .026) controlling for physical activity. Follow-up univariate analysis of covariance revealed that the younger group produced significantly greater peak torque for all concentric extension conditions. Eccentric trunk strength was somewhat preserved in the older group. Age-related changes in trunk strength were independent of physical activity. The normal loss of trunk muscle strength in older age is muscle- and contractile-mode specific. These findings provide guidance for effective intervention strategies to offset adverse health outcomes related to trunk strength loss in older adults.

Physical Abilities in Low Back Pain Patients: A Cross-Sectional Study with Exploratory Comparison of Patient Subgroups

An abundance of literature has investigated the association between low back pain (LBP) and physical ability or function. It has been shown that LBP patients display reduced range of motion, decreased balance ability, impaired proprioception, and lower strength compared to asymptomatic persons. The aim of this study was to investigate the differences between LBP patients and healthy controls in terms of several physical abilities. Based on the premised that different biomechanical and physiological causes and consequences could be related to different types of LBP, a secondary exploratory attempt of the study was to examine the differences between LBP subgroups based on the pain location (local or referred) or type of pathology (discogenic or degenerative) on the level of impairment of function and ability. Participants performed range of motion tests, trunk maximal voluntary contraction force tests, a sitting balance assessment, the timed up-and-go test, the chair rise test, and the trunk reposition error test. Compared to the control group, symptomatic patients on average showed 45.7% lower trunk extension (p < 0.001, η² = 0.33) and 27.7 % lower trunk flexion force (p < 0.001, η² = 0.37) during maximal voluntary contraction. LBP patients exhibited decreased sitting balance ability and lower scores in mobility tests (all p < 0.001). There were no differences between groups in Schober’s test and trunk repositioning error (p > 0.05). No differences were observed among the LBP subgroups. The exploratory analyses are limited by the sample size and uncertain validity of the diagnostic procedures within this study. Further studies with appropriate diagnostic procedures and perhaps a different subgrouping of the LBP patients are needed to elucidate if different types of LBP are related to altered biomechanics, physiology, and function.

Isokinetic Trunk Strength in Acute Low Back Pain Patients Compared to Healthy Subjects: A Systematic Review

BACKGROUND

The purpose of this systematic review was to: (I) determine the quality of evidence from studies assessing trunk isokinetic strength in subjects with acute low back pain (ALBP) compared to healthy subjects and (II) establish reference values of isokinetic trunk strength in subjects with ALBP.

METHODOLOGY

Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statements were followed using keywords associated with trunk, strength and low back pain. Four databases were used: PubMed, Web of Science, Scopus and SPORTDiscus. Methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS).

RESULTS

A total of 1604 articles were retrieved, four included in this review. All were evaluated as high risk of bias (Rob). Due to the high Rob and the diversity of protocols, instruments and variables used, it was not possible to determine reference values for subjects with ALBP, we can only establish a range of flexion peak torque (PT) between 175.1 and 89.7 Nm at 60°/s and between 185 and 81.5 Nm at 120°/s, and for extension PT between 240.0 and 91.5 Nm at 60°/s and between 217.5 and 69.2 Nm at 120°/s in subjects with ALBP.

CONCLUSIONS

Due to the low quality of the evidence and the diversity of protocols used when measuring trunk isokinetic strength, it is necessary to carry out new high-quality research to establish reference values of trunk strength in subjects with ALBP.

Comparison of the Effectiveness of Three Lumbosacral Orthoses on Early Spine Surgery Patients: A Prospective Cohort Study

Objective

To compare the convenience and effectiveness of the existing lumbosacral orthoses (LSO) (classic LSO and Cybertech) and a newly developed LSO (V-LSO) by analyzing postoperative data.

Methods

This prospective cohort study was performed from May 2019 to November 2019 and enrolled and analyzed 88 patients with degenerative lumbar spine disease scheduled for elective lumbar surgery. Three types of LSO that were provided according to the time of patient registration were applied for 6 weeks. Patients were randomized into the classic LSO group (n=31), Cybertech group (n=26), and V-LSO group (n=31). All patients were assessed using the Oswestry Disability Index (ODI) preoperatively and underwent plain lumbar radiography (anteroposterior and lateral views) 10 days postoperatively. Lumbar lordosis (LS angle) and frontal imbalance were measured with and without LSO. At the sixth postoperative week, a follow-up assessment with the ODI and orthosis questionnaire was conducted.

Results

No significant differences were found among the three groups in terms of the LS angle, frontal imbalance, ODI, and orthosis questionnaire results. When the change in the LS angle and frontal imbalance toward the reference value was defined as a positive change with and without LSO, the rate of positive change was significantly different in the V-LSO group (LS angle: 41.94% vs. 61.54% vs. 83.87%; p=0.003).

Conclusion

The newly developed LSO showed no difference regarding its effectiveness and compliance when compared with the existing LSO, but it was more effective in correcting lumbar lordosis.

Association of low back pain with muscle weakness, decreased mobility function, and malnutrition in older women: A cross-sectional study

Background

Low back pain (LBP) and decreased mobility function are common problem among older people. Muscle weakness has been reported as a risk factor for these conditions, and exercise therapy can improve them. We created a novel exercise device that also measures abdominal trunk muscle strength. Malnutrition has also emerged as a major problem among older people. Muscle is a direct key linking decreased mobility function and malnutrition. This study aimed to examine the associations of LBP with not only decreased physical function and muscle weakness but also nutritional status of older people.

Methods

We examined the associations of LBP with muscle weakness, decreased mobility function (locomotive syndrome [LS]), and malnutrition among older women. The study included 101 female patients aged 60 years or older scheduled to undergo surgery for degenerative lower extremity diseases. Preoperatively, physical tests including abdominal trunk muscle strength assessment using the device and laboratory tests were conducted. Subjects with LBP (numerical rating scale ≥2; range, 0–4) during the preceding month were allocated to the LBP group (n = 36). Other subjects were allocated to the non-LBP group (n = 65).

Results

The LBP group had lower abdominal trunk and knee extensor muscle strength, lower serum albumin, and hemoglobin levels as blood biomarkers associated with malnutrition risk, and higher LS test scores than the non-LBP group. A multivariate analysis showed that abdominal trunk muscle weakness and advanced LS were associated with LBP. LBP intensity was negatively correlated with abdominal trunk and knee extensor muscle strength and positively correlated with the LS test score. The serum hemoglobin level was negatively correlated with the LS test score.

Conclusion

Abdominal trunk muscle weakness and decreased mobility function were associated with LBP among older women.

Physical Performance, Anthropometrics and Functional Characteristics Influence the Intensity of Nonspecific Chronic Low Back Pain in Military Police Officers

Background: Chronic low back pain (CLBP) is a serious problem in Military Police Officers (MPO), which accounts for up to 45% of the sick leave rates. It has been assumed that the strength and the endurance of trunk flexor and extensor muscles are CLPB key factors, but it is not known whether these attributes are related to pain intensity. It was aimed to determine whether the strength and endurance of trunk flexor and extensor muscles differ in MPO with no pain (CON; n = 24), moderate (MOD; n = 42), and severe (SEV; n = 37) nonspecific chronic low back pain (CLBP). Methods: The peak torque and endurance test of trunk flexor (PTF.BM⁻¹) and extensor (PTE.BM⁻¹) muscles were compared. A multiple regression analysis was used to identify pain intensity predictors in all groups (PAIN) and according to pain intensity (MOD and SEV). Results: The PTF.BM⁻¹ was negatively related to pain and was a significant predictor, irrespective of pain intensity (PAIN). Conclusion: When pain intensity was considered the PTF.BM⁻¹ and PTE.BM⁻¹ explained the pain in the MOD, while the PTE.BM⁻¹ and service time explained pain intensity in the SEV. Endurance of the flexor and extensor muscles was not related to pain intensity. These results indicated that training protocols must emphasize specific strengthening routines.

Muscular fitness is associated with spinal pain among young people: A cross-sectional exploratory study

PURPOSE

the aim of this study was to analyze the association between upper limb muscular fitness and spinal pain in the cervical, thoracic, and lumbar regions among young people.

METHODS

Cross-sectional study involving a probabilistic sample of 1054 participants (547 female) with ages ranging from 10 to 17 years, from Brazil. The dependent variable was pain in the cervical, thoracic, and lumbar regions of the spine, assessed by a self-report instrument. The independent variable was muscular fitness, verified using the 90° push-up test with the cut-offs proposed by FITNESSGRAM. The covariates were age, sex, socioeconomic status, physical activity, and body mass index. Ordinal logistic regression was adopted to conduct the multivariate association and estimate the Odds Ratios (OR). Two separate analyses were conducted: one with the whole sample and the other with only participants who reported pain.

RESULTS

The prevalences of spine pain in the cervical, thoracic, and lumbar regions were 24.4, 28.3, and 31.0%. In the whole sample, young people who achieved the criterion-referenced standard for muscular fitness were less likely to present high intensity pain in the thoracic region (OR = 0.67, 0.50-0.90). The same occurred when analyzing only those who reported pain for cervical region (OR = 0.48, 0.29-0.79). No association was found between muscular fitness and lumbar pain.

CONCLUSIONS

Upper limb muscular fitness can be used as an additional tool to prevent high levels of spine pain in the thoracic region among young people as well as the severity of cervical pain in those who report pain.

Evaluation isometric and isokinetic of trunk flexor and extensor muscles with isokinetic dynamometer: A systematic review

OBJECTIVE

To systematically review the literature analyzing the reliability and characteristics of the protocols of isokinetic and isometric evaluation of the trunk flexor and extensor muscles with isokinetic dynamometer.

METHODS

This is a systematic review using PubMed, CENTRAL, LILACS, PEDro and SCOPUS databases, searching the oldest records up to December 2019. The risk of bias, the methodological quality and the level of evidence were evaluated using the COSMIN checklist.

RESULTS

Fourteen articles have met the criteria and have been included in this study. All the articles performed an isometric or isokinetic evaluation of the trunk muscles with the isokinetic dynamometer and presented an analysis of the protocol's reliability using the intraclass correlation coefficient. Five articles had excellent reliability (0.93-0.98). Most of the studies presented doubtful and inconsistent psychometric values for reliability, because they used a short period between tests. The level of evidence to the fourteen selected articles for reliability was moderate.

CONCLUSIONS

Although the studies present limitations in methodological quality, it was possible to identify highly reliable patterns in the parameters employed and to present recommendations for the assessment of trunk flexor and extensor muscles in the isokinetic dynamometer, both for assessment in the sitting position and orthostatic.

Increased Liveliness of Trunk Muscle Responses in Elite Kayakers and Canoeists

Trunk stability functions play an important role in sport and everyday movements. The aim of this study was to analyze trunk strength, trunk muscles onset of activity, and rate of electromyographic rise (RER) in the case of self-inflicted and unexpected trunk loading. Thirty-two healthy young adults (16 elite kayakers/canoeists and 16 non-athletes) were measured with a multi-purpose diagnostic machine. Trunk strength was assessed in standing position. Trunk muscles onset of activity and RER were assessed through unexpected loading over the hands and rapid shoulder flexion, respectively. In comparison with non-athletes, kayakers/canoeists did not significantly differ in trunk strength and showed lower trunk extension/flexion strength ratio (p = 0.008). In general, trunk muscles onset of activity did not significantly differ between the groups. On the contrary, kayakers/canoeists showed higher RER mean values in all the observed muscles (p < 0.041), except in multifidus muscle during self-inflicted movements. Similarly, higher RER variability was observed in the majority of the observed muscles among kayakers/canoeists. Higher RER among kayakers/canoeists could represent a protective mechanism that ensures spine stability and prevents low back pain.

Chronic Fatigue, Physical Impairments and Quality of Life in Women with Endometriosis: A Case-Control Study

AIM

To explore endometriosis-related fatigue (ERF), health-related fitness, sleep quality, and health-related quality of life (HRQoL) in women with endometriosis in comparison with matched controls.

METHODS

Twenty-five affected women and twenty-five age and height-matched women without endometriosis were included. ERF was assessed through the Piper Fatigue Scale; health-related fitness was assessed through the Schöber, flamingo, and 6-min walking tests and dynamometry; and body composition was assessed through impedanciometry. Self-perceived physical fitness, sleep quality, and HRQoL were assessed through the International Fitness Scale, the Pittsburgh Sleep Quality Index, and the 12-item Short Form Health Survey, respectively.

RESULTS

Affected women exhibited higher levels of ERF than controls, increased fat mass, and physical deconditioning (reduced back strength, lumbar flexibility, body balance, and functional capacity, p-values < 0.050). Moreover, cases also had poorer perceived physical fitness, sleep quality, and HRQoL (p-value < 0.050). Finally, we observed deteriorated health-related fitness, sleep quality, and HRQoL in those women with endometriosis with higher levels of ERF.

CONCLUSIONS

This study constitutes the first evidence that women with endometriosis describe a generalized physical deconditioning, even more pronounced in affected women with higher levels of ERF. Further studies assessing the efficacy of rehabilitation interventions to face these physical impairments in women with endometriosis are warranted.

Core Stability and Symmetry of Youth Female Volleyball Players: A Pilot Study on Anthropometric and Physiological Correlates

The aim of the present study was to examine the variation in core stability and symmetry of youth female volleyball players by age, and its relationship with anthropometric characteristics, the 30 s Wingate anaerobic test (WAnT), and the 30 s Bosco test. Female volleyball players (n = 24, age 13.9 ± 1.9 years, mean ± standard deviation) performed a series of anthropometric, core stability tests (isometric muscle endurance of torso flexors, extensors, and right and left lateral bridge), WAnT (peak power, mean power, Pmean, and fatigue index, FI) and Bosco test (Pmean). Flexors-to-extensors ratio and right-to-left lateral bridge ratio were also calculated. Participants were grouped into younger (n = 12, 12.3 ± 1.2 years) or older than 14 years (n = 12, 15.4 ± 1.0 years), and into normal (flexors-to-extensors ratio < 1; n = 17) or abnormal flexors-to-extensors ratio (≥1; n = 7). The older age group was heavier (+11.3 kg, mean difference; 95% CI, 2.0, 20.6) and with higher body mass index (+2.8 kg m−2; 95% CI, 0.4, 5.1) than the younger age group. The group with abnormal flexors/extensors had larger flexors muscle endurance (+77.4 s; 95% CI, 41.8, 113.0) and higher flexors/extensors ratio (+0.85; 95% CI, 0.61, 1.10) than the normal group. Body fat percentage (BF) correlated moderately-to-largely with flexors (r = −0.44, p = 0.033), extensors (r = −0.51, p = 0.011), and left lateral bridge (r = −0.45, p = 0.027); WAnT Pmean moderately-to-largely with right (r = 0.46, p = 0.027) and left lateral bridge (r = 0.55, p = 0.006); FI moderately-to-largely with right (r = −0.45, p = 0.031) and left lateral bridge (r = −0.67, p < 0.001), and right/left ratio (r = 0.42, p = 0.046); Bosco Pmean correlated moderately-to-largely with right (r = 0.48, p = 0.020) and left lateral bridge (r = 0.67, p = 0.001). A stepwise regression analysis indicated FI and BF as the most frequent predictors of core stability. The findings of the present study suggested that increased core stability was related to decreased BF and increased anaerobic capacity. A potential misbalance between torso flexors and extensors might be attributed to bidirectional variations (either high or low scores) of flexors muscle endurance rather than decreased extensors muscle endurance.

Trunk Muscle Activation Patterns Differ Between Those With Low and High Back Extensor Strength During a Controlled Dynamic Task

It is proposed that reduced function in one of the spinal systems (active, passive, and neural) outlined by Panjabi could increase the risk of experiencing a low back injury (LBI). Also proposed is that reduced function in any one system can be compensated for by adjusting the time-varying recruitment of trunk muscles. This study addressed whether those with reduced active system function (WEAK), measured as back extensor strength, would have different trunk muscle activation patterns than those with higher function (STRONG), and secondly whether this relationship would be modified following recovery from a LBI. Sixty men participated, 30 recently recovered from LBI (rLBI, 4–12 weeks post injury) and 30 who had not had a LBI in the last year (ASYM). ASYM and rLBI participants were separated into STRONG and WEAK sub-groups if their isometric back extensor strength was above or below their group median, respectively. Trunk electromyograms from 24 muscle sites were recorded during a highly controlled horizontal transfer task. Principal component analysis captured key muscle activation patterns (amplitude and temporal); then analysis of variance models tested for strength or group*strength effects on these patterns consistent with the two main objectives. Significant strength, or group by strength effects were found for 3/4 electromyographic comparisons. In general, the WEAK group required higher activation amplitudes of abdominal and back extensor muscles, and greater temporal responsiveness of back extensor muscles only to the changing external moments than those who were STRONG. Group by strength interactions found that participants in the rLBI group had greater differences between WEAK and STRONG participants for overall muscle activation amplitudes in both abdominal and back extensor muscles. This increase in muscle activation was interpreted as compensation for lower maximum force properties whereas the increased temporal responsiveness captured a greater need to modify the agonist back extensors muscle activation patterns only in response to changes in the dynamic moments. Interactions captured that the recent experience of pain (rLBI) modified the magnitude of adjustment in muscle activation patterns potentially adapting to an increased risk of instability (painful flare) events associated with a deficit (lower strength) of the active system.

Which trunk exercise most effectively activates abdominal muscles? A comparative study of plank and isometric bilateral leg raise exercises

BACKGROUND

Various forms of trunk exercise have been used for increasing abdominal strength. The plank exercise and bilateral leg raise exercise are one of these trunk exercises. However, there are few studies that compared the effects of these exercise variations.

OBJECTIVE

The present study aimed to investigate how effectively the trunk muscles during plank and bilateral leg raise exercises are activated.

METHOD

Surface electromyography responses of the rectus abdominis, internal oblique, and erector spinae muscles were investigated during the plank and bilateral leg raise exercise with different hip position. A total of 18 healthy, physically active female volunteers completed the normal plank exercise, plank exercise with placing the lower leg in a horizontal condition, bilateral leg raise exercise, and bilateral leg raise with lower leg as horizontal condition.

RESULTS

The horizontal condition caused significant increases in activity of the internal oblique muscles compared with the general condition (p< 0.05). The bilateral leg raise exercise showed significantly greater activation in the rectus abdominis compared to the plank exercise (p< 0.05).

CONCLUSION

The present study showed that the horizontal condition had the advantage of activating the internal oblique muscles, and the leg raise exercise is effective in strengthening global muscle such as the rectus abdominis.

Can High-Intensity Functional Suspension Training over Eight Weeks Improve Resting Blood Pressure and Quality of Life in Young Adults? A Randomized Controlled Trial

The present study examined the effects of a functional high-intensity suspension training (Functional_HIIT) on resting blood pressure, psychological well-being as well as on upper body and core strength and cardiorespiratory fitness in moderately trained participants. Twenty healthy, moderately trained adults (10 males and 10 females; age: 36.2 ± 11.1 years, BMI: 23.9 ± 3.7) were randomly assigned to a Functional_HIIT training group or passive control group (CON). Functional_HIIT performed 16 sessions (2× week for eight weeks, 30 min per session), whereas CON maintained their habitual lifestyle using a physical activity log. Before and after Functional_HIIT intervention, resting blood pressure and quality of life (short version of the WHO Quality of Life questionnaire (WHOQOL-BREF)) were assessed. Furthermore, maximum-repetition (leg press, chest press, pulldown, back extension) and trunk muscle strength (Bourban test) as well as cardiorespiratory fitness (Vameval test), were measured before and after the intervention. Both systolic and diastolic blood pressure and WHOQOL-BREF did not change significantly but both showed moderate training-induced effects (0.62 < standardized mean difference (SMD) < 0.82). Significant improvements in the Functional_HIIT group were evident on leg press (p < 0.01), chest press (p < 0.05), and left side Bourban test (p < 0.05). Cardiorespiratory fitness did not reveal any time effects or time × group interactions. The present study revealed that eight weeks of Functional_HIIT represents a potent stimulus to improve health-related parameters in young adults, whereas Functional_HIIT was not sufficient to improve cardiorespiratory fitness.