Isokinetic trunk strength and lumbosacral range of motion in elite female field hockey players reporting low back pain

Factors associated with non-specific low back pain in field hockey: A cross-sectional study of Premier and Division One players

OBJECTIVE

To determine the extent to which various factors are associated with greater or lesser odds of reporting non-specific low back pain (NS-LBP) in field hockey.

METHODS

To meet the objective of the study, a cross-sectional study design was used with a purposive sampling strategy. A total of 194 responses (~18% of those accessible) from Premier and Division One players within the UK were received using a UK-based online survey. Data collected included information on NS-LBP, participant characteristics, injury history, training related factors, and work and personal factors. The overall and category-specific prevalence of NS-LBP was calculated. Univariable and multivariable logistic regression was used in conjunction with clinical value to identify associations.

RESULTS

The overall prevalence of NS-LBP was 44.0%, with this varying from 23.5 to 70.0% for categories with responses of "yes" and "no" to experiencing NS-LBP. A total of ten individual factors associated with a greater odds ratio (OR) of reporting NS-LBP (OR = 1.43-7.39) were identified in Premier and Division One players. Five individual factors were associated with reduced odds (OR = 0.11-0.60) of reporting NS-LBP. Seven factors (age, stature, playing position, playing internationally, performing a drag flick, low back stiffness/tightness and occupational factors) were deemed particularly pertinent to those working in field hockey given the magnitude of association and clinical value to clinicians.

CONCLUSIONS

Clinicians working in field hockey can consider the key risk factors identified in this study that are associated with NS-LBP when assessing injury risk, movement screening approaches, and overall athlete management.

Monitoring modifiable injury risk factors over an in-season mesocycle in semi-professional female field hockey players

OBJECTIVE

This study aimed to determine changes of modifiable injury risk factors and fatigue parameters during a mesocycle (4 months of the competitive season) in semi-professional female field hockey players (Spanish 2nd Division).

METHODS

Fourteen female field hockey players (age: 22.6 ± 4.9 years) participated in the study over 4 months of the competitive season (September-December 2019). The players were tested each month for their: maximal isometric knee flexion, hip adduction, and abduction muscle strength; passive straight leg raise and ankle dorsiflexion range of motion (ROM); countermovement jump height; and perceptual fatigue (through a perceived well-being questionnaire).

RESULTS

Statistical differences were reported in isometric knee flexion torque in the dominant and non-dominant limb (p = < 0.001, ηp2 = 0.629,0.786 respectively), non-dominant isometric hip abductors torque (p = 0.016, ηp2 = 0.266) and isometric hip adductors torque in dominant and non-dominant limbs (p = < 0.001, ηp2 = 0.441-546). Also, significant differences were reported in the straight leg raise test (p = < 0.001, ηp2 = 0-523, 0.556) and ankle dorsiflexion (p = 0.001, ηp2 = 0.376, 0.377) for the dominant and non-dominant limb respectively. Finally, the jump height measured showed significant differences (p = <.001, ηp2 = 0.490), while no differences were reported in perceived well-being parameters (p = 0.089-0.459).

CONCLUSION

Increments in isometric muscle strength and fluctuations in ROM values and vertical jumping capacity are reported over an in-season mesocycle (i.e., 4 months of the competitive season). This information can be used to target recovery strategies to make them more efficient.

Assessment of Neuromuscular and Psychological Function in People with Recurrent Neck Pain during a Period of Remission: Cross-Sectional and Longitudinal Analyses

The aim of this study was to examine for the presence of differences in neuromuscular and psychological function in individuals with recurrent neck pain (RNP) or chronic neck pain (CNP) following a whiplash trauma compared to healthy controls. A secondary aim was to examine whether neuromuscular characteristics together with psychological features in people with RNP were predictive of future painful episodes. Multiple features were assessed including neck disability, kinesiophobia, quality of life, cervical kinematics, proprioception, activity of superficial neck flexor muscles, maximum neck flexion and extension strength, and perceived exertion during submaximal contractions. Overall, those with RNP (n = 22) and CNP (n = 8) presented with higher neck disability, greater kinesiophobia, lower quality of life, slower and irregular neck movements, and less neck strength compared to controls (n = 15). Prediction analysis in the RNP group revealed that a higher number of previous pain episodes within the last 12 months along with lower neck flexion strength were predictors of higher neck disability at a 6-month follow-up. This preliminary study shows that participants with RNP presented with some degree of altered neuromuscular features and poorer psychological function with respect to healthy controls and these features were similar to those with CNP. Neck flexor weakness was predictive of future neck disability.

Elbow varus torque and ball velocity associations in high school and professional pitchers with increased sagittal-plane trunk tilt

BACKGROUND

Increased sagittal-plane trunk tilt is thought to increase drive in the anterior direction toward home plate, transferring energy from the trunk to the distal upper extremity, ultimately generating greater ball velocity. Increased sagittal trunk tilt has also been implicated in the risk of upper-extremity joint loading in baseball pitchers by way of elbow varus torque (EVT), a metric previously associated with elbow injury in professional pitchers. The purposes of this study were (1) to compare sagittal trunk tilt positioning between high school and professional pitchers throughout the pitch and (2) to identify the potential associations between sagittal-plane trunk tilt, ball velocity, and EVT for both cohorts.

METHODS

Professional and high school pitchers were instructed to throw fastballs while being evaluated with 3-dimensional motion capture (480 Hz). Sagittal trunk tilt motion throughout the pitching motion was compared between cohorts from maximum knee height to maximum shoulder internal rotation. To assess the effects of sagittal-plane trunk tilt on ball velocity and EVT, linear mixed-effect models were created.

RESULTS

Professional pitchers (n = 100, 882 pitches) achieved greater sagittal trunk tilt than high school pitchers (n = 57, 519 pitches) during early portions of the pitching motion, including maximum positive sagittal trunk tilt (46.6° ± 8.3° vs. 43.6° ± 10.2°, P = .042). Professional pitchers also had greater sagittal trunk tilt excursion throughout the pitch motion (68.0° ± 11.4° vs. 62.5° ± 11.0°, P = .004). For every 10° increase in sagittal trunk tilt at ball release for professional pitchers, ball velocity increased by 0.36 m/s (B = 0.036 and β = 0.194, P < .001) or 0.9% average ball velocity whereas EVT increased by 0.14% body weight × body height (B = 0.014 and β = 0.159, P < .001) or 2.9% average normalized EVT. For every 10° increase in sagittal trunk tilt at ball release for high school pitchers, ball velocity increased by 0.34 m/s (B = 0.097 and β = 0.025, P = .025) or 1.1% average ball velocity whereas EVT increased by 0.07% body weight × body height (B = 0.007 and β = 0.086, P = .016) or 1.7% average normalized EVT.

CONCLUSION

Increased positive sagittal-plane trunk tilt was significantly associated with greater ball velocity and increased EVT for both professional and high school pitchers. Peak EVT estimates were consistently more pronounced than ball velocity benefits for both populations, suggesting that no specific time point may provide a ball velocity benefit while concomitantly minimizing EVT. Both professional and high school pitchers should consider this trade-off, which may influence injury risk, when engaging in higher degrees of positive sagittal-plane trunk tilt.

Movement patterns and neuromusculoskeletal impairments observed in a female Olympic Field Hockey team: An observational cohort study

PURPOSE

The purpose of the cross-sectional observational cohort study was to quantify movement patterns and neuromuscular impairments in Olympic Female Field Hockey utilizing a standardized movement-centered assessment model.

METHODOLOGY/SAMPLE

A sample of convenience was obtained from the active roster of the 2016 USA Women's Olympic Field Hockey team. Inclusion and exclusion criteria were applied and resulted in nine participants. The study was conducted over 1 session in which each athlete was tested using the SFMA™, Y Balance Test Lower Quarter (YBT-LQ™) FMS™, and closed chain dorsiflexion range of motion (CKCDFROM). Injury risk assignment was generated based on an evidenced based algorithm. Descriptive statistics and frequency distributions were applied to the subjects.

RESULTS

Injury risk stratification was applied to the subjects with 44% being at moderate risk and 56% at slight risk. 100% of the athletes exhibited spinal extension deficits and 89% of the athletes displayed a dysfunctional single leg stance pattern. Regional impairments included the following observations: anterior hip mobility deficits (5/9 subjects) and rolling motor control dysfunction (7/9 subjects).

IMPLICATIONS

A battery of movement centered tests combined with an evidenced based algorithm can provide meaningful information informing future programming for the elite female athlete. Considering regional interdependence applications, impairments at the hip and thoracic spine, combined with poor quality of movement in extension could create undue stress in remote regions of the spine and lower quarter, thus contributing to injury risk for the spine and lower quarter.

Are neuromuscular adaptations present in people with recurrent spinal pain during a period of remission? a systematic review

A plethora of evidence supports the existence of neuromuscular changes in people with chronic spinal pain (neck and low back pain), yet it is unclear whether neuromuscular adaptations persist for people with recurrent spinal pain when in a period of remission. This systematic review aimed to synthesise the evidence on neuromuscular adaptations in people with recurrent spinal pain during a period of remission. Electronic databases, grey literature, and key journals were searched from inception up to the 4^th of September 2020. Eligibility criteria included observational studies investigating muscle activity, spine kinematics, muscle properties, sensorimotor control, and neuromuscular performance in adults (≥ 18 years) with recurrent spinal pain during a period of remission. Screening, data extraction, and quality assessment (Newcastle-Ottawa Scale) were conducted independently by two reviewers. Data synthesis was conducted per outcome domain. A meta-analysis with a random-effects model was performed where possible. The overall strength of evidence was rated using the Grading of Recommendations, Assessment, Development and Evaluation guidelines (GRADE). From 8292 records, 27 and five studies were included in a qualitative and quantitative synthesis, respectively. Very low level of evidence supports muscle activity changes in people with recurrent low back pain, especially greater co-contraction, redistribution of muscle activity, and delayed postural control of deeper trunk muscles. Reduced range of motion of the lumbar spine was also found. Meaningful conclusions regarding other outcome domains or people with recurrent neck pain could not be drawn. In conclusion, people with recurrent low back pain during a period of remission show muscle activity and spine kinematics adaptations. Future research should investigate the long-term impact of these changes, as well as adaptations in people with recurrent neck pain.

Muscle Strength and Neuromuscular Control in Low-Back Pain: Elite Athletes Versus General Population

The purpose of the study was to investigate the athletic-based specificity of muscle strength and neuromuscular control of spine stability in chronic non-specific low-back pain (LBP). Thirty elite athletes and 29 age-matched non-athletes with (15 athletes and 15 non-athletes) and without LBP (15 athletes and 14 non-athletes) participated in the study. Muscle strength was measured during maximal isometric trunk flexion and trunk extension contractions. The neuromuscular control of spine stability was analyzed by determining trunk stiffness, trunk damping, and onset times of the lumbar and thoracic erector spinae muscles after sudden perturbations (quick release experiments) as well as maximum Lyapunov exponents (local dynamic stability) using non-linear time series analysis of repetitive lifting movements. LBP was assessed using the visual analog scale. We found lower maximal trunk extension moments (p = 0.03), higher trunk damping (p = 0.018) and shorter onset times (p = 0.03) of the investigated trunk muscles in LBP patients in both athletes and non-athletes. Trunk stiffness and the local dynamic stability did not show any differences (p = 0.136 and p = 0.375, respectively) between LBP patients and healthy controls in both groups. It can be concluded that, despite the high-level of training in athletes, both athletes and non-athletes with LBP showed the same deconditioning of the lumbar extensor muscles and developed similar strategies to ensure spine stability after sudden perturbations to protect the spine from pain and damage. The findings highlight that specific training interventions for the trunk muscles are not only crucial for individuals of the general population, but also for well-trained athletes.

Is there evidence to use kinematic/kinetic measures clinically in low back pain patients? A systematic review

BACKGROUND

Currently, there is a widespread reliance on self-reported questionnaires to assess low back pain patients. However, it has been suggested that objective measures of low back pain patients' functional status should be used to aid clinical assessment. The aim of this study is to systematically review which kinematic /kinetic parameters have been used to assess low back pain patients against healthy controls and to propose clinical kinematic/kinetic measures.

METHODS

PubMed, Embase and Scopus databases were searched for relevant studies. Reference lists of selected studies and hand searches were performed. Studies had to compare people with and without non-specific low back pain while performing functional tasks and report body segment/joint kinematic and/or kinetic data. Two reviewers independently identified relevant papers.

FINDINGS

Sixty-two studies were included. Common biases identified were lack of assessor blinding and sample size calculation, use of samples of convenience, and poor experimental protocol standardization. Studies had small sample sizes. Range of motion maneuvers were the main task performed (33/62). Kinematic/kinetic data of different individual or combination of body segments/joints were reported among the studies, commonest was to assess the hip joint and lumbar segment motion (13/62). Only one study described full body movement. The most commonly reported outcome was range of motion. Statistically significant differences between controls and low back pain groups were reported for different outcomes among the studies. Moreover, when the same outcome was reported disagreements were noted.

INTERPRETATION

The literature to date offers limited and inconsistent evidence of kinematic/kinetic measures in low back pain patients that could be used clinically.

An exploratory examination of the association between altered lumbar motor control, joint mobility and low back pain in athletes

Background:

Low back pain (LBP) is a common cause of lost playing time and can be a challenging clinical condition in competitive athletes. LBP in athletes may be associated with joint and ligamentous hypermobility and impairments in activation and coordination of the trunk musculature, however there is limited research in this area.

Objectives:

To determine if there is an association between altered lumbar motor control, joint mobility and low back pain (LBP) in a sample of athletes.

Materials and Methods:

Fifteen athletes with LBP were matched by age, gender and body mass index (BMI) with controls without LBP. Athletes completed a questionnaire with questions pertaining to demographics, activity level, medical history, need to self-manipulate their spine, pain intensity and location. Flexibility and lumbar motor control were assessed using: active and passive straight leg raise, lumbar range of motion (ROM), hip internal rotation ROM (HIR), Beighton ligamentous laxity scale, prone instability test (PIT), observation of lumbar aberrant movements, double leg lowering and Trendelenburg tests. Descriptive statistics were compiled and the chi square test was used to analyze results.

Results:

Descriptive statistics showed that 40% of athletes with LBP exhibited aberrant movements (AM), compared to 6% without LBP. 66% of athletes with LBP reported frequently self-manipulating their spine compared to 40% without LBP. No significant differences in motor control tests were found between groups. Athletes with LBP tended to have less lumbar flexion (63 ± 11°) compared to those without LBP (66 ± 13°). Chi-Square tests revealed that the AM were more likely to be present in athletes with LBP than those without (X2 = 4.66, P = 0.03).

Conclusions:

The presence of aberrant movement patterns is a significant clinical finding and associated with LBP in athletes.

In-chair movement: validity, reliability and implications for measuring sitting discomfort

Sitting discomfort is traditionally evaluated with subjective rating scales which are referenced to an objective correlate (e.g. sitting posture) measured on a static (i.e. non-continuous) basis. Since sitting discomfort is dynamic in nature, it requires continuous, objective measurement. We therefore adapted an interface pressure mat to continuously record in-chair movement (ICM) as an indirect measurement of sitting discomfort by tracking the center of pressure (COP) at the buttock-chair interface. Here we report on two phases in the development of the COP system: laboratory validity and field reliability. In the laboratory study we confirmed system validity by simultaneously tracking ICM with the mat and a force platform (r2 > 0.80) and by comparing subjects' COP movement with their gross trunk movements (r2 > 0.86). In our field study we used the intraclass correlation coefficient to establish a data sampling (i.e. selection) protocol that was reliable. We collected ICM data on seated telecommunications Directory Assistance operators during 2 h field tests. Results showed that using a minimum sampling time of 5 min and then averaging a series of 5 min samples of ICM was more reliable than single discrete samples. Using the averaging protocol, we also showed that ICM increased significantly over 2 h and that ICM did not differ between trials.

[Multidisciplinary treatment program for chronic low back pain, part 2. Somatic aspects]

PROBLEM

There is a great need to expand current knowledge of the various functional capacity measurements used in the rehabilitation of chronic low back pain (CLBP) patients. The literature on these patients reports that mobility, endurance, trunk strength and lifting capacity decrease during the process of chronicity. Chronically disabled patients appear to have lower functional capacity than asymptomatic persons.

METHODS

Our study group consisted of 90 disabled CLBP patients (44 female, 46 male; average age 42 years) who underwent a multidisciplinary 8-week daily treatment program of functional restoration with behavioral support (instruction, endurance training, strength exercises, behavioral and treatment to facilitate return to work therapy). Initially these patients where compared with 107 asymptomatic persons (44 female, 63 male, average age 41 years). The patients were investigated before and after treatment, and at intervals of 6 and 12 months. The reliability of the functional measurements was evaluated by interrater comparison. Physical assessment included a medical examination (mainly diagnosis of radicular or nonradicular pain), changes in the lumbar spine revealed by X-ray studies according to Herron and Turner, rating of physical impairment according to Waddell, flexibility, length of hamstrings muscles (SLR), test of power and endurance of trunk movement by standardized exercises according to the Swiss group of Spring and isokinetic measurements (LIDO Back), tests of lifting capacity (LIDO Lift), and (in part) of general endurance on a cycle ergometer (CASE 15 Marquette).

RESULTS

Physical findings showed that mobility was reduced substantially in patients suffering from back pain due to reduced SLR (shortened hamstrings) and decreased spinal mobility. Patients also demonstrated significant reductions in their ability to perform lifting tasks in comparison to healthy individuals. The results of trunk flexion showed no significant differences between patients and the control group, whereas the ability to perform trunk extension was much better in the control group. In principle we found the same results with isokinetic measurements as in the exercises without machines. Cardiovascular endurance was also much better in the control group than it was in the back pain patients. At the end of the treatment program all physical deficits were improved significantly. In many cases performance was comparable with that of the control group. With time, however, training effects gradually decreased. The success of treatment (return to work, absence from work, pain reduction, use of medical care) was independent of the functional status of the patients before and after treatment.

CONCLUSION

Study results showed that physical capacity in disabled patients with low back pain is substantially reduced in comparison to persons who do not suffer from back pain. The only exception was in trunk flexor strength and endurance, in which measurements did not differ between the patients and the control group. However, even CLBP- patients with long-term pain and severe physical illness can successfully improve their physical condition by participating in an active treatment program. Back extensor muscle training has to be included in physical therapy. Because of loss of condition during the time after treatment, regular monitoring of patients and their home training programs is necessary. Overall, treatment of CLBP has to include physical training and psychosocial treatment to achieve satisfactory results.

Influence of hamstring length on the standing position and flexion range of motion of the pelvic angle, lumbar angle, and thoracic angle

Hamstring muscle length may be associated with specific pelvic and trunk postures, but the influence of hamstring length on trunk postures is not well documented. The purposes of this study were to examine the influence of hamstring length on 1) the pelvic angle, lumbar angle, and thoracic angle in standing; and 2) the flexion ranges of motion of the pelvic angle, lumbar angle, and thoracic angle during the toe-touch test. Surface platform pointers over bony landmarks and photography were used to examine the pelvic and trunk angles and ranges of motion of 10 men with short hamstrings, 10 men with medium hamstrings, and 10 men with long hamstrings while standing and after assuming the toe-touch position. Separate one-way analyses of variance detected no significant differences among groups for the three angles in standing. Significant differences were detected among groups for the three angles in the toe-touch position and the flexion ranges of motion during the toe-touch test (p < 0.05). Short hamstrings were associated with decreased flexion range of motion of the pelvic angle and lumbar angle and increased flexion range of motion of the thoracic angle. Therapeutic interventions should be considered in light of the influences of hamstring length on the flexion range of motion of the pelvic angle, lumbar angle, and thoracic. angle.