Isometric hip abduction using a Thera-Band alters gluteus maximus muscle activity and the anterior pelvic tilt angle during bridging exercise

Effects of pelvic tilt control using visual biofeedback on gluteus maximus, multifidus, and hamstring activities during three different bridge exercises

BACKGROUND

The effects of pelvic tilt control using visual biofeedback on gluteus maximus (GM), multifidus (MF), and hamstring (HAM) muscle activities during bridge exercises involving anterior pelvic tilt (APT), neutral pelvic tilt (NPT), and posterior pelvic tilt (PPT) were investigated.

METHODS

Twenty-five healthy participants were included (mean age, 24.6 ± 1.9 years). Visual biofeedback was used for the participants to self-control pelvic tilt during the bridge exercises. Pelvic tilt controls were performed in a random order (APT vs. NPT vs. PPT) following 30 minutes education program. GM, MF, and HAM muscle activities were measured by surface electromyography. One-way repeated analysis of variance and Bonferroni post hoc test were used.

RESULT

GM and MF muscle activities significantly differed among the different pelvic tilting controls (APT vs. NPT vs. PPT) (p < .017). GM muscle activity during the exercise involving PPT was significantly higher than that involving APT and NPT (p < .017). In contrast, MF muscle activity during the exercise involving PPT was significantly lower than that involving APT (p < .017). In addition, the GM/Right MF, GM/Left MF, and GM/HAM muscle activity ratios during the exercise involving PPT were significantly greater than those involving APT and NPT (p < .017).

CONCLUSIONS

The bridge exercise involving PPT using visual biofeedback can be recommended as a home exercise to selectively improve the muscle activity of the GM and the muscle activity ratio of the GM/HAM and GM/MF. This information may be valuable for clinicians seeking exercise programs to target specific muscles effectively.

Trunk muscle activation in prone plank exercises with different body tilts

BACKGROUND

Body tilt changes could affect the intensity/difficulty of core stability exercises, but there is still a lack of knowledge about its impact.

OBJECTIVE

To analyse the trunk muscles activation during prone plank exercises at different body tilts.

METHODS

Twenty-four young adults who performed recreational gymnastic activities participated in this study. Electromyography activity of the rectus abdominis (RA), external oblique (EO), internal oblique (IO) and erector spinae (ES) was recorded during the performance of six variations of the prone plank exercise (planking with feet supported on the ground [conventional horizontal position] and planking with feet supported on wall bars at five different heights increasing the angle tilt) and an inverted position exercise.

RESULTS

The RA, EO and IO activation in all prone plank variations were higher than those observed in the conventional prone plank. In addition, the coefficient of variation of the muscle activation increased with the declination angle, reaching the highest values in the inverted position for the RA and ES muscles.

CONCLUSION

The results seem to indicate that the body tilt variation could be used as an easy and inexpensive strategy for modulating the neuromuscular demands and the motor control challenge during planking exercises.

The correlation of clinical status and imaging findings in patients with chronic low back pain

Background/Aim: Chronic low back pain (LBP) is a common health problem that negatively affects quality of life. A multidisciplinary approach is recommended in treating chronic LBP. In the literature, we could not find any study examining the relationship between clinical status, activities of daily living, angular measurements in the lumbar region, and spondylosis level in patients with LBP. We aimed to reveal whether there is a relationship between the severity of the clinical condition and these angular measurements. In addition, there are opposing views in the literature about the relationship between obesity and LBP, and we planned to investigate this issue in our study. We aimed to investigate the correlation between clinical, functional evaluations, and radiographic findings in patients with chronic LBP and examine the relationship between these variables and gender and educational level. We also determine the effects of age, body mass index (BMI), and waist circumference on these variables. Methods: The research was designed as a cross-sectional, uncontrolled study. Seventy patients aged 18–65 years with chronic LBP and VAS (Visual Analog Scale) values ≥ 3 were included. Patients were grouped by gender and educational level. Lumbar lordosis angle (LLA), sacral inclination angle (SIA), and Kellgren-Lawrence (K-L) grade were recorded. VAS, Oswestry Disability Index (ODI), Back Pain Functional Scale (BPFS), and Katz Activities of Daily Living (Katz-ADL) scores were calculated. Pearson correlation analysis determined the normal distribution status of the variables. Spearman’s correlation analysis evaluated the linear relationship between ODI and BPFS and LLA and SIA continuous variables. A p-value of < 0.05 was considered statistically significant. Results: A total of 70 patients (47 females and 23 males) with chronic LBP were included in the study. Mean BMI (28.2 [6.1] kg/m2) and waist circumference (95.7 [12.7] cm) of the patients were above normal ranges (normal BMI: 18.5–24.99 kg/m², normal waist circumference: < 80 cm for women, < 90 cm for men). Katz-ADL (P = 0.006) and BPFS scores (P = 0.027) were lower, and LLA (P = 0.042) was higher in women than men. The BPFS score was lower in the low-level education group than in the high-level education group (P = 0.004). There was a positive correlation between age and SIA (P = 0.028, r = 0.262), and between age and K-L grade (P < 0.001, r = 0.633). A positive correlation was also observed between BMI and K-L grade (P = 0.001, r = 0.395) and waist circumference and K-L grade (P < 0.001, r = 0.442). Conclusion: No correlation was found between functional clinical scales and radiographic findings in patients with chronic LBP. Increasing age, BMI, and waist circumference were associated with more severe radiographic osteoarthritis of the lumbar spine, whereas female gender and low educational level were related to lower functional levels. Further extensive studies, including a larger number of patients, are needed to clarify our results.

Effects of Knee Flexion Angles on the Joint Force and Muscle Force during Bridging Exercise: A Musculoskeletal Model Simulation

Bridging exercise is commonly used to increase the strength of the hip extensor and trunk muscles in physical therapy practice. However, the effect of lower limb positioning on the joint and muscle forces during the bridging exercise has not been analyzed. The purpose of this study was to use a musculoskeletal model simulation to examine joint and muscle forces during bridging at three different knee joint angle positions. Fifteen healthy young males (average age: 23.5 ± 2.2 years) participated in this study. Muscle and joint forces of the lumbar spine and hip joint during the bridging exercise were estimated at knee flexion angles of 60°, 90°, and 120° utilizing motion capture data. The lumbar joint force and erector spinae muscle force decreased significantly as the angle of the knee joint increased. The resultant joint forces were 200.0 ± 23.2% of body weight (%BW), 174.6 ± 18.6% BW, and 150.5 ± 15.8% BW at 60°, 90°, and 120° knee flexion angles, respectively. On the other hand, the hip joint force, muscle force of the gluteus maxims, and adductor magnus tended to increase as the angle of the knee joint increased. The resultant joint forces were 274.4 ± 63.7% BW, 303.9 ± 85.8% BW, and 341.1 ± 85.7% BW at a knee flexion angle of 60°, 90°, and 120°, respectively. The muscle force of the biceps femoris decreased significantly with increased knee flexion during the bridging exercise. In conclusion, the knee flexion position during bridging exercise has different effects on the joint and muscle forces around the hip joint and lumbar spine. These findings would help clinicians prescribe an effective bridging exercise that includes optimal lower limb positioning for patients who require training of back and hip extensor muscles.

Relationship between cam morphology, hip symptoms, and hip osteoarthritis: the Musculoskeletal pain in Ullersaker STudy (MUST) cohort

BACKGROUND

The primary aim of this study was to determine the prevalence of cam morphology in a cohort of people aged 40-55 years. Secondary aims were to: (1) determine differences in participant characteristics, physical impairments, radiographic and ultrasound appearances of people with and without cam morphology; and (2) explore associations between cam morphology and radiographic measures of hip osteoarthritis (OA).

METHODS

107 people (68% women; 49 ± 4 years) from the Musculoskeletal pain in Ullensaker (MUST) Study underwent the clinical and imaging examinations. Examinations included questionnaires, hip range, functional task performance, pelvic radiographs and ultrasound. Alpha angle and radiographic hip OA (Kellgren Lawrence (KL) and minimal joint space (MJS)) were determined.

RESULTS

The prevalence of cam morphology was 42% and was bilateral in 47%. People with cam morphology were 6 times more likely to have a KL score ⩾2 (adjusted odds ratio [95% confidence intervals, p-value]) 6.386 [1.582-37.646, p = 0.012]) and 4 times more likely to have MJS <2.0 mm (adjusted odds ratio 4.032 [1.031-12.639, p = 0.045]). The prevalence of radiographic OA features ranged from 4-13% in people with cam morphology, and 0-3% in those without. Those with cam morphology also demonstrated reduced hip flexion and rotation range (p = 0.018-0.036) compared with those without. There was no association between ultrasonic features and patient reported outcomes, and cam morphology.

CONCLUSIONS

In a cohort aged 40-55 years, the prevalence of cam morphology was high (42%), with a significant relationship between cam morphology and radiographic measures of hip OA. Further longitudinal studies should explore the relationship between cam morphology and hip OA in younger people.

How effective is an evidence-based exercise intervention in individuals with patellofemoral pain?

OBJECTIVES

Guidelines for a comprehensive rehabilitation programme for patellofemoral pain (PFP) have been developed by international experts. The aim of this study was to analyse the effect of such a rehabilitative exercise programme on pain, function, kinesiophobia, running biomechanics, quadriceps strength and quadriceps muscle inhibition in individuals with PFP.

DESIGN

Observational study.

SETTING

Clinical environment.

PARTICIPANTS

Twenty-seven participants with PFP.

MAIN OUTCOME MEASURES

Symptoms [numeric pain rating scale (NPRS)and the pain subscale of the Knee Injury and Osteoarthritis Outcome Score (KOOS)], function measured by using the KUJALA scale and KOOS, kinesiophobia measured by using the Tampa scale, three-dimensional biomechanical running data, quadriceps isometric, concentric and eccentric strength and arthrogenic muscle inhibition (AMI) were acquired before and after the six-week exercise programme.

RESULTS

Although pain did not significantly improve all patients were pain-free after the six-week exercise programme (NPRS: p = 0.074). Function, kinesiophobia and quadriceps AMI improved significantly after the six-week exercise programme (KUJALA: p = 0.001, KOOS: p = 0.0001, Tampa: p = 0.017, AMI: p = 0.018). Running biomechanics during stance phase did not change after the exercise intervention. Quadriceps strength was not different after the six-week exercise programme (isometric: p = 0.992, concentric: p = 0.075, eccentric: p = 0.351).

CONCLUSION

The results of this study demonstrate that the current exercise recommendations can improve function and kinesiophobia and reduce pain and AMI in individuals with PFP. There is a need for reconsideration of the current exercise guidelines in stronger individuals with PFP.

Muscle activation in pelvic anteversion and retroversion

Abstract Introduction: The inability to maintain good pelvic stability has been attributed to inefficient muscle coordination and deconditioning of the stabilizing muscles. Despite this, little is known about the role of the pelvic muscles in anteversion and retroversion movements. Objective: To compare the neuromuscular activity of the tensor fascia lata, gluteus medius, upper and lower portions of the gluteus maximus, and multifidus in pelvic anteversion and retroversion. Methods: The neuromuscular activity of 17 healthy young adults (aged 25.3 ± 4.6 years) was assessed during five repetitions of the pelvic anteversion and retroversion movements. The Vicon-Nexus system (10 cameras) was used for the kinematic analysis of the pelvis in the sagittal plane (anteversion and retroversion), and the TeleMyo DTS Desk Receiver electromyograph and the Myomuscle v. 3.8 software to measure neuromuscular activity. The paired samples t-test was used to compare muscle activity between pelvic anteversion and retroversion movements using the Statistica v.8 software with a significance level of p < 0.05. Results: The comparison of the movements showed greater muscle activity in the inferior gluteus maximus in retroversion and greater activity in the multifidus in pelvic anteversion. The upper portion of the gluteus maximus showed relevant activation in both movements. Conclusion: There was more pronounced activity of the lower portion of the gluteus maximus in retroversion, while the upper gluteus maximus showed relevant activation level in both movements. The multifidi were more active in retroversion.

A Comparison of the Transient Effect of Complex and Core Stability Exercises on Static Balance Ability and Muscle Activation during Static Standing in Healthy Male Adults

Balance ability is a necessary exercise factor required for the activities of daily living. This study investigated the effects of short-term complex exercise (CE) and core stability exercise (CSE) on balance ability and trunk and lower-extremity muscle activation on healthy male adults. Twenty-nine healthy male adults were included. All performed CE and CSE for 1 min each; the exercise order was randomized. The primary and secondary outcomes were balance ability and muscle activation, respectively. In balance ability, CE showed a significant difference in all variables in both eye-opened and eye-closed conditions compared with the baseline (p < 0.05). In comparisons among exercises, the path length and average velocity variables showed a significant decrease in the eye-opened condition, and the path length variable showed a significant decrease in the eye-closed condition (p < 0.05). In muscle activation, CE showed a significant increase in the gluteus medius (Gmed) and decrease in the rectus femoris (RF), tibialis anterior (TA), and RF/biceps femoris (BF) ratio in the eye-opened condition compared to the baseline and a significant decrease in RF and RF/BF ratio in the eye-closed condition (p < 0.05). Both CE and CSE improved the static balance ability. Furthermore, muscle activation significantly increases in Gmed and decreases in the RF, TA, and RF/BF ratio. Therefore, we recommend including CE in an exercise program that has the purpose of improving static balance ability.

Asymmetrical fatiguing of the gluteus maximus muscles in the elite short-track female skaters

Background

According to research, fast skating on short distances increases functional asymmetry of leg muscles. As has been proven in many sporting disciplines, this asymmetry can increase the risk of injury. The aim of the study was to analyze the level of right and left myolectrical manifestations of fatigue asymmetry of gluteus maximus muscle in elite skaters on a short track and to compare this phenomenon to a control group. The muscles were chosen deliberately, due to their influence in maintaining the right position during training on ice.

Methods

The experiment compared a group of eight members of the Polish Women’s National Team in short track with a group of eight non-training people. The subjects did the Biering-Sorensen test, in which sEMG (surface electromyography) signal frequency was measured in the gluteus maximus muscles during an isometric contraction. Myolectrical manifestations of fatigue slopes were analyzed with a ANOVA with repeated measures. In the skaters, the myolectrical manifestations of fatigue differed between the right and the left gluteus maximus muscles. All the skaters had higher myolectrical manifestations of fatigue in the right leg. This phenomenon was not observed in the non-training subjects, who on average had similar myolectrical manifestations of fatigue in both legs.

Results

Results showed that the right and the left muscles of the skaters in the experimental group differed in myolectrical manifestations of fatigue, but this difference was non-significant in the control group.

The subjects from the two groups did not differ in the myolectrical manifestations of fatigue of the left muscle, they did in the myolectrical manifestations of fatigue of the right muscle. The elite speed-track skaters had higher myolectrical manifestations of fatigue in the right muscle than the non-training subjects.

Conclusions

Training should thus be planned in a way that minimizes the risk of causing muscle myolectrical manifestations of fatigue asymmetry in skaters despite the typically asymmetrical muscle work during training on ice and competition, thus new training protocols should be developed or considered to decrease that asymmetry.

Trial registration

The tests were previously approved by the Bioethical Commission of the Chamber of Physicians in Opole. (Resolution No. 235 of 13 December 2016).

Effects of knee flexion angles in supine bridge exercise on trunk and pelvic muscle activity

This study investigated the activity of surface electromyography (sEMG) on trunk and pelvic muscles during supine bridge exercise (SBE) with different knee flexion angles. Twenty-five physically active males participated in this study. Subjects received maximum voluntary isometric contraction (MVIC) tests followed by four SBEs with different knee flexion angles (40°, 60°, 90° and 120°) in random. sEMG activities of rectus abdominis (RA), erector spinae (ER), gluteus medius (GMed), superior gluteus maximus (SGMax), inferior gluteus maximus (IGMax), biceps femoris (BF) long head, and the ratio of SGMax/BF and IGMax/BF on the dominant side were measured. Non-clinical magnitude-based inference was performed to compare the effect. The results indicated a substantial change of muscle activity, especially between SBE with 40° and 120° knee flexion. With respect to ER and BF, moderate effect (-0.70 ± 0.17) and extremely large effect (-4.78 ± 0.51) were recorded, whereas very large effect for SGMax/BF (2.68 ± 0.23) and IGMax/BF (2.95 ± 0.26) was observed, respectively. Both ER and BF worked better with smaller knee flexion angles (40° > 60° > 90° > 120°), while SGMax and IGMax were more favourable to SBE with large knee flexion angles (90° = 120° > 60° > 40°).

Effects of Different Sling Settings on Electromyographic Activities of Selected Trunk Muscles: A Preliminary Research

Introduction

The supine and prone sling exercise may facilitate activation of the local trunk muscles. Does the side-lying sling exercise activate trunk muscles more easily than the supine and prone training with sling settings? Clinical work has shown that the side-lying sling exercise could reduce pain in patients with unilateral low back pain (LBP), but the mechanism behind it is unclear. The fundamental purpose of this preliminary study was to examine the electromyography (EMG) characteristics of trunk muscles during different sling lumbar settings on sixteen healthy adults.

Methods

Amplitude and mean power frequency (MPF) of EMG signals were recorded from the transversus abdominis (TA), rectus abdominis (RA), multifidus (MF), erector spinae (ES), gluteus maximus (Gmax), and gluteus medius (Gmed) muscles while the subjects performed the supine lumbar setting (SLS), prone lumbar setting (PLS), left side-lying lumbar setting (LSLS), and right side-lying lumbar setting (RSLS).

Results

During SLS and PLS, TA and MF showed significantly higher activity than RA and ES on the same side, respectively. The EMG activities of ES, TA, MF, Gmax, and Gmed had significant differences between the different sides during LSLS and RSLS, and the dominant-side muscles showed higher activity than the other side. There was no significant difference in core trunk muscles between different sling lumbar settings-only that the SLS of the MF/ES ratio was significantly higher than LSLS and RSLS.

Conclusions

Sling exercises can be an effective measure to enhance MF and TA EMG activity, and the side-lying position can increase dominant-side Gmax and Gmed activity. Side-lying sling training does not activate more core muscles than the supine and prone training. Supine and prone exercise should be preferred over SLT to stabilize the lumbar region because of its high local/global muscle ratio.

The effects of abdominal drawing-in maneuver during stair climbing on muscle activities of the trunk and legs

The purpose of this study was to investigate effects of abdominal drawing-in maneuver (ADIM) on the muscular activity of the trunk and the lower limbs during stair ascent. The subjects were healthy 15 men and 8 women who were in their 20s. After maintaining ADIM by using a pressure biofeedback unit for 15 min, the subjects performed stair ascent and their muscular activity of the right trunk and the legs was measured to determine difference between when the subjects maintained ADIM and did not. The activities of the sternocleidomastoid, the splenius capitis, the rectus abdominis (ABD), the external abdominal oblique (EO), the transverse abdominis (TRA), the elector spinae (ES), the vastus medialis (VM), and the vastus lateralis (VL) were measured using surface electromyogram (TM DTS). The collected data were statistically processed by the SPSS ver. 18.0 and analyzed with a paired t-test. The muscular activities of the TRA, VM, and VL significantly increased (P<0.05), while the activity of the ES significantly decreased (P<0.05) during stair ascent when the ADIM was maintained than when it was not. In conclusion, the stair ascent with ADIM maintained activated the abdominal muscles to control trunk balance and perform lumbar stability, simultaneously reducing excessive lumbar lordosis or pelvic anterior tilt which will help to improve the function of the musculoskeletal system.

Effects of Resistive Jaw-Opening Exercise with Elastic Bands on Suprahyoid Muscle Activation in Normal Subjects

OBJECTIVE

The effect of a resistive jaw-opening exercise using an elastic band on suprahyoid muscle activity and tongue strength was examined in healthy volunteers.

METHODS

Twenty-one adults wore an elastic loop around their head and mandible. To prescribe the appropriate elastic band resistance, the 10-repetition maximum (10 RM) was measured among 4 bands at baseline. Band loops, starting with the highest resistance value band, were sequentially applied to determine the suitability for 10 RM. During the exercise, the participants were required to open their jaw maximally and maintain the position for 10 s; then, they rested for 10 s. This procedure was repeated for 20 min, 3 days per week for 8 weeks to test suprahyoid muscle activation during effortful swallowing; isometric tongue pressures of the tongue tip and base at baseline, after 4, and after 8 weeks of training were measured.

RESULTS

Peak suprahyoid muscle activation amplitudes during effortful swallow and isometric pressures at the tongue tip significantly increased after 8 weeks.

CONCLUSION

The 8-week resistive jaw-opening exercise significantly improved strength of the suprahyoid muscle and tongue pressures in healthy subjects. These positive results warrant further investigation of the therapeutic effects and feasibility of this resistive exercise.

Thera-Band application changes muscle activity and kyphosis and scapular winging during knee push-up plus in subjects with scapular winging: The cross-sectional study

Scapular winging (SW) is defined as increased prominence of the whole medial border of the scapula. Many researchers recently recommended knee push-up plus (KPP) for enhancing serratus anterior (SA) activation. However, during push-up plus, thoracic kyphosis (TK) may usually occur as a compensatory movement. Thus, the purpose of this study was to investigate the effect of Thera-Band application during KPP on rectus abdominis (RA) activity, TK angle (TKA), SA activity, and amount of SW in subjects with SW.Fifteen subjects performed KPP with Thera-Band applied to different posterior body parts (no Thera-Band, in the occiput, and in the thoracic region). Electromyography was used to record the RA and SA activities. Image J software was used to calculate the compensatory TKA during KPP, and a scapulometer was used to measure SW in the quadruped position. One-way repeated-measures analysis of variance was used to test for significance.KPP with Thera-Band in the occiput showed significantly lower RA activity (P = .001) and TKA (P < .001) than KPP with no Thera-Band. SA activity (P = .020, P = .047) and SW (P < .001, P < .001) were significantly lower with Thera-Band applied to the occiput and thoracic regions than in KPP with no Thera-Band.Thera-Band applied to the occiput and thorax can be beneficial as it decreases RA and SA muscle activity and reduces TKA and SW during KPP in subjects with SW.

Effect of modified bridge exercise on trunk muscle activity in healthy adults: a cross sectional study

•

Bridge exercise with unstable surface increases trunk muscle activities.

•

Bridge exercise with hip abduction increases trunk muscles activities.

•

Modified bridge exercises are useful for co-activation of trunk muscles.

Design

This is a cross-sectional study.

Setting

University research laboratory.

Participants

Fifteen healthy adults (mean age: 27.47 years) volunteered for this study.

Intervention

The individuals performed standard bridge exercise and modified bridge exercises with right leg-lift (single-leg-lift bridge exercise, single-leg-lift bridge exercise on an unstable surface, and single-leg-lift hip abduction bridge exercise).

Main outcome measures

During the bridge exercises, electromyography of the rectus abdominis, internal oblique, erector spinae, and multifidus muscles was recorded using a wireless surface electromyography system. Two-way repeated-measures analysis of variance (exercise by side) with post hoc pairwise comparisons using Bonferroni correction was used to compare the electromyography data collected from each muscle.

Results

Bilateral internal oblique muscle activities showed significantly greater during single-leg-lift bridge exercise (95% confidence interval: right internal oblique = −8.99 to −1.08, left internal oblique = −6.84 to −0.10), single-leg-lift bridge exercise on an unstable surface (95% confidence interval: right internal oblique = −7.32 to −1.78, left internal oblique = −5.34 to −0.99), and single-leg-lift hip abduction bridge exercise (95% confidence interval: right internal oblique = −17.13 to −0.89, left internal oblique = −8.56 to −0.60) compared with standard bridge exercise. Bilateral rectus abdominis showed greater electromyography activity during single-leg-lift bridge exercise on an unstable surface (95% confidence interval: right rectus abdominis = −9.33 to −1.13, left rectus abdominis = −4.80 to −0.64) and single-leg-lift hip abduction bridge exercise (95% confidence interval: right rectus abdominis = −14.12 to −1.84, left rectus abdominis = −6.68 to −0.16) compared with standard bridge exercise. In addition, the right rectus abdominis muscle activity was greater during single-leg-lift hip abduction bridge exercise compared with single-leg-lift bridge exercise on an unstable surface (95% confidence interval = −7.51 to −0.89). For erector spinae, muscle activity was greater in right side compared with left side during all exercises (95% confidence interval: standard bridge exercise = 0.19–4.53, single-leg-lift bridge exercise = 0.24–10.49, single-leg-lift bridge exercise on an unstable surface = 0.74–8.55, single-leg-lift hip abduction bridge exercise = 0.47–11.43). There was no significant interaction and main effect for multifidus.

Conclusions

Adding hip abduction and unstable conditions to bridge exercises may be useful strategy to facilitate the co-activation of trunk muscles.

The effects of visual biofeedback using ultrasonograpy on deep trunk muscle activation

[Purpose] The objective of this study is to investigate the effect of visual biofeedback using ulatrasonography on the functional improvement of deep trunk muscle. [Subjects and Methods] This study selected ten healthy people without orthopedic history and information on the study. The average ages, heights, and weights were 22.70 ± 2.06 years old, 171.15 ± 9.18 cm, and 66.86 ± 8.88 kg in the experimental group, respectively. The abdominal drawing-in maneuver were executed for subjects through monitoring the status of muscle contraction using ultrasonic waves. And motor control exercises were performed during 6 weeks, 20 minutes/day and three times/week. We collected the data using electromyography MP150 system (BIOPAC system Inc., CA, USA) in order to measure trunk muscle activation. [Results] The subjects showed significant improvements in Internal oblique abdominis and lumbar multifidus muscle after intervention. [Conclusion] Visual biofeedback training using ultrasonography might be effective in improving function of the deep trunk muscle.

Changes in the activity of trunk and hip extensor muscles during bridge exercises with variations in unilateral knee joint angle

[Purpose] This study compared abdominal and hip extensor muscle activity during a bridge exercise with various knee joint angles. [Subjects and Methods] Twenty-two healthy male subjects performed a bridge exercise in which the knee joint angle was altered. While subjects performed the bridge exercise, external oblique, internal oblique, gluteus maximus, and semitendinosus muscle activity was measured using electromyography. [Results] The bilateral external and internal oblique muscle activity was significantly higher at 0° knee flexion compared to 120°, 90°, and 60°. The bilateral gluteus maximus muscle activity was significantly different at 0° of knee flexion compared to 120°, 90°, and 60°. The ipsilateral semitendinosus muscle activity was significantly increased at 90° and 60° of knee flexion compared to 120°, and significantly decreased at 0° knee flexion compared with 120°, 90°, and 60°. The contralateral semitendinosus muscle activity was significantly higher at 60° of knee flexion than at 120°, and significantly higher at 0° of knee flexion than at 120°, 90°, and 60°. [Conclusion] Bridge exercises performed with knee flexion less than 90° may be used to train the ipsilateral semitendinosus. Furthermore, bridge exercise performed with one leg may be used to train abdominal and hip extensor muscles.

Effects of isometric hip movements on electromyographic activities of the trunk muscles during plank exercises

[Purpose] The purpose of this study was to investigate the effect of isometric hip adduction and abduction on trunk muscle activity during plank exercises. [Subjects and Methods] Nineteen healthy male subjects were recruited for this study. All subjects performed the traditional plank exercise (TP), plank exercise with isometric hip adduction (PHAD), and plank exercise with isometric hip abduction (PHAB) by using an elastic band. Electromyographic (EMG) activities of the internal oblique (IO) and external oblique (EO) were measured during the 3 plank exercises by using an Electromyography system. [Results] Internal oblique and external oblique muscle activities were significantly greater during plank exercise with isometric hip adduction and plank exercise with isometric hip abduction than during traditional plank exercise. Internal oblique and external oblique muscle activities did not differ between the plank exercise with isometric hip adduction and plank exercise with isometric hip abduction conditions. [Conclusion] These findings demonstrate that loaded isometric hip movements may be a useful strategy to increase trunk muscle activity during plank exercises.

A comparative study of the effects of trunk exercise program in aquatic and land-based therapy on gait in hemiplegic stroke patients

[Purpose] The purpose of this study was to compare the effects of aquatic and land-based trunk exercise program on gait in stroke patients. [Subjects and Methods] The subjects were 28 hemiplegic stroke patients (20 males, 8 females). The subjects performed a trunk exercise program for a total of four weeks. [Results] Walking speed and cycle, stance phase and stride length of the affected side, and the symmetry index of the stance phase significantly improved after the aquatic and land-based trunk exercise program. [Conclusion] These results suggest that the aquatic and land-based trunk exercise program may help improve gait performance ability after stroke.

Comparison of EMG activity on abdominal muscles during plank exercise with unilateral and bilateral additional isometric hip adduction

The aim of this study was to investigate the effects of additional isometric hip adduction during the plank exercise on the abdominal muscles. Twenty healthy young men participated in this study. Surface electromyography (EMG) was used to monitor the activity of the bilateral rectus abdominis (RA), the internal oblique (IO), and the external oblique (EO) muscles. The participants performed three types of plank exercise; the standard plank exercise, the plank exercise with bilateral isometric hip adduction, and the plank exercise with unilateral isometric hip adduction. All abdominal muscle activity was significantly increased during the plank exercise combined with the bilateral and unilateral isometric hip adduction compared with the standard plank exercise (p<0.05). Bilateral IO, EO, and left RA muscle activity was significantly increased during the unilateral isometric hip adduction compared with the bilateral isometric hip adduction (p<0.05). These findings suggest that additional isometric hip adduction during the plank exercise could be a useful method to enhance abdominal muscle activity. In particular, the unilateral isometric hip adduction is a more beneficial exercise than the bilateral isometric hip adduction.

Effects of trajectory exercise using a laser pointer on electromyographic activities of the gluteus maximus and erector spinae during bridging exercises

[Purpose] The purpose of this study was to investigate activities of the hip extensors and erector spinae during bridging exercise by using instruments with a laser pointer on the pelvic belt. [Subjects] Twelve subjects (age, 23 to 33 years) with non-specific low back pain volunteered for this study. [Methods] Subjects performed bridging exercises with and without trajectory exercises by using a laser pointer fixed to a pelvic strap. The erector spinae, gluteus maximus and hamstring activities with and without trajectory exercises using a laser pointer were recorded on using electromyography. [Results] Compared to the without laser pointer group, the group that underwent bridging with trajectory exercises using a laser pointer had significantly higher gluteus maximus activity and significantly lower erector spinae activity. Significantly higher gluteus maximus/erector spinae activity ratios were observed when performing trajectory exercises using a laser pointer during bridging exercises. [Conclusion] This result suggests that trajectory exercises using a laser pointer during a bridging exercise would be effective for improving gluteus maximus activity.

Modifying the hip abduction angle during bridging exercise can facilitate gluteus maximus activity

PURPOSE

To investigate how the erector spinae (ES) and gluteus maximus (GM) muscle activity and the anterior pelvic tilt angle change with different hip abduction angles during a bridging exercise.

METHODS

Twenty healthy participants (10 males and 10 females, aged 21.6 ± 1.6) voluntarily participated in this study. Surface electromyography (EMG) signals were recorded from the ES and GM during bridging at three hip abduction angles: 0°, 15°, and 30°. Simultaneously, the anterior pelvic tilt angle was measured using Image J software.

RESULTS

The EMG amplitude of the GM muscle and the GM/ES EMG ratio were greatest at 30° hip abduction, followed by 15° and then 0° hip abduction during the bridging exercise. In contrast, the ES EMG amplitude at 30° hip abduction was significantly lesser than that at 0° and 15° abduction. Additionally, the anterior pelvic tilt angle was significantly lower at 30° hip abduction than at 0° or 15°.

CONCLUSIONS

Bridging with 30° hip abduction can be recommended as an effective method to selectively facilitate GM muscle activity, minimize compensatory ES muscle activity, and decrease the anterior pelvic tilt angle.

A comparison of two gluteus maximus EMG maximum voluntary isometric contraction positions

Background. The purpose of this study was to compare the peak electromyography (EMG) of the most commonly-used position in the literature, the prone bent-leg (90°) hip extension against manual resistance applied to the distal thigh (PRONE), to a novel position, the standing glute squeeze (SQUEEZE).

Methods. Surface EMG electrodes were placed on the upper and lower gluteus maximus of thirteen recreationally active females (age = 28.9 years; height = 164 cm; body mass = 58.2 kg), before three maximum voluntary isometric contraction (MVIC) trials for each position were obtained in a randomized, counterbalanced fashion.

Results. No statistically significant (p < 0.05) differences were observed between PRONE (upper: 91.94%; lower: 94.52%) and SQUEEZE (upper: 92.04%; lower: 85.12%) for both the upper and lower gluteus maximus. Neither the PRONE nor SQUEEZE was more effective between all subjects.

Conclusions. In agreement with other studies, no single testing position is ideal for every participant. Therefore, it is recommended that investigators employ multiple MVIC positions, when possible, to ensure accuracy. Future research should investigate a variety of gluteus maximus MVIC positions in heterogeneous samples.