Activation of the gluteus maximus,gluteus medius and tensor fascia lata muscles during hip internal and external rotation exercises at three hip flexion postures

BackgroundHip internal and external rotation exercises are usually performed in clinical practice. However, given the synergies required to stabilize the hip in the frontal plane, it is not clear how the activation of target muscles will differ between the two exercise directions.ObjectiveI) Compare the activation of the upper and lower fibers of gluteus maximus (GMax), gluteus medius (GMed) and tensor fascia lata muscles between the hip internal and external rotation exercises; ii) Compare the maximal isometric force between hip internal and external rotation exercises and; iii) Assess the effect of varying hip flexion angles on muscle activation and maximal isometric force.Study designA cross sectional study.MethodsElectromyography and force production of twenty-one participants were measured during maximum isometric hip internal and external rotation in three postures: 0°, 45° and 90° of hip flexion.ResultsMANOVA results showed a larger activation of the GMed, tensor fascia lata and upper GMax (p < .001) for hip internal rotation compared to external rotation regardless of hip flexion angle. For the lower GMax, the same was observed when the hip was kept at 90° of flexion. Maximal isometric force during hip external rotation was greater than during hip internal rotation at 0° posture, and lower at 90° posture (p < .001).ConclusionThe gluteus and the tensor fascia lata muscles were substantially recruited during the hip internal rotation exercise, and barely recruited during the hip external rotation exercise. Hip flexion influences the myoeletric activity and isometric force production during the internal rotation exercise.     

Immediate effects of elongation training using an elastic band on the hip abductor muscles

[Purpose] This study investigated the effects of elongation training on the hip abductor muscles in comparison with the effects of general hip abductor training. [Participants and Methods] This study included 39 healthy male university students. The participants were divided into elongation training and general-weighted hip abduction training groups. An elastic band was used for elongation training, and hip abduction exercises were performed with instructions to extend the foot as far as possible to stretch the band. Measurements were taken before and after training, and the surface electromyographic data of the gluteus medius and the tensor fasciae latae were measured during isometric contraction of the hip abductor muscles. The surface electromyogram data were used to calculate integral values and median power frequencies to compare the effects of training. [Results] In comparison with general hip abductor training, elongation training yielded a larger change in the ratio of muscle integral values (gluteus medius/tensor fasciae latae). [Conclusion] Elongation training of the hip abductor muscles was more useful than general training in increasing the activity of the gluteus medius while suppressing the activity of the tensor fasciae latae.     

Hip abduction machine is better than free weights to target the gluteus medius while minimizing tensor fascia latae activation

IntroductionChanges in the lower extremities’ biomechanics are associated with gluteus medius (GMed) weakness and increased tensor fascia latae (TFL) activation.ObjectiveTo determine which exercises produce greater GMed activity while minimizing TFL activation during the concentric and eccentric phases of three single-joint strengthening exercises.DesignControlled laboratory study.SettingLaboratory.ParticipantsEleven males (age: 29.18 ± 4.51 years; body mass: 84.01 ± 14.48 kg; height: 1.74 ± 0.07 m; body fat: 16.34 ± 3.33%).Main outcome measuresGMed and TFL activation and activation ratio while performing ten maximal repetitions of three exercises: side-lying hip abduction (SLHA); clamshell (CLAM) and hip abductor machine (HAM).ResultsGMed activation was greater than TFL in all exercises in both concentric and eccentric phases. There were no differences in GMed activation between the three exercises in both phases. TFL activation was greater in SLHA compared to HAM and CLAM during both phases. In both concentric and eccentric phases, GMed:TFL ratio was greater in HAM compared to CLAM and SLHA.ConclusionsGMed had increased activation compared to TFL in all analyzed exercises. Considering GMed:TFL ratio, if the goal is to preferentially activate GMed while minimizing TFL activation, the hip abductor machine seems to be the best exercise.     

Examining Muscle Activity Differences During Single and Dual Vector Elastic Resistance Exercises

BackgroundElastic resistance exercise is a common part of rehabilitation programs. While these exercises are highly prevalent, little information exists on how adding an additional resistance vector with a different direction from the primary vector alters muscle activity of the upper extremity.PurposeThe purpose of this study was to examine the effects of dual vector exercises on torso and upper extremity muscle activity in comparison to traditional single vector techniques.Study DesignRepeated measures design.MethodsSixteen healthy university-aged males completed four common shoulder exercises against elastic resistance (abduction, flexion, internal rotation, external rotation) while using a single or dual elastic vector at a fixed cadence and standardized elastic elongation. Surface electromyography was collected from 16 muscles of the right upper extremity. Mean, peak and integrated activity were extracted from linear enveloped and normalized data and a 2-way repeated measures ANOVA examined differences between conditions.ResultsAll independent variables differentially influenced activation. Interactions between single/dual vectors and exercise type affected mean activation in 11/16 muscles, while interactions in peak activation existed in 7/16 muscles. Adding a secondary vector increased activation predominantly in flexion or abduction exercises; little changes existed when adding a second vector in internal and external rotation exercises. The dual vector exercise in abduction significantly increased mean activation in lower trapezius by 25.6 ± 8.11 %MVC and peak activation in supraspinatus by 29.4 ± 5.94 %MVC (p<0.01). Interactions between single/dual vectors and exercise type affected integrated electromyography for most muscles; the majority of these muscles had the highest integrated electromyography in the dual vector abduction condition.ConclusionMuscle activity often increased with a second resistance vector added; however, the magnitude was exercise-dependent. The majority of these changes existed in the flexion and abduction exercises, with little differences in the internal or external rotation exercises.Level of Evidence3b     

AN EXAMINATION OF THE GLUTEAL MUSCLE ACTIVITY ASSOCIATED WITH DYNAMIC HIP ABDUCTION AND HIP EXTERNAL ROTATION EXERCISE: A SYSTEMATIC REVIEW

Background

A wide variety of hip abduction and hip external rotation exercises are used for training, both in athletic performance and in rehabilitation programming. Though several different exercises exist, a comprehensive understanding of which exercises best target the gluteus maximus (Gmax) and gluteus medius (Gmed) and the magnitude of muscular activation associated with each exercise is yet to be established.

Purpose

The purpose of this systematic review was to quantify the electromyographic (EMG) activity of exercises that utilize the Gmax and Gmed muscles during hip abduction and hip external rotation.

Methods

Pubmed, Sports Discuss, Web of Science and Science Direct were searched using the Boolean phrases (gluteus medius OR gluteus maximus) AND (activity OR activation) AND (electromyography OR EMG) AND (hip abduction OR hip external rotation). A systematic approach was used to evaluate 575 articles. Articles that examined injury‐free participants of any age, gender or activity level were included. No restrictions were imposed on publication date or publication status. Articles were excluded when not available in English, where studies did not normalize EMG activity to maximum voluntary isometric contraction (MVIC), where no hip abduction or external rotation motion occurred or where the motion was performed with high acceleration.

Results

Twenty‐three studies met the inclusion criteria and were retained for analysis. The highest Gmax activity was elicited during the lateral step up, cross over step up and rotational single leg squat (ranging from 79 to 113 % MVIC). Gmed activity was highest during the side bridge with hip abduction, standing hip abduction with elastic resistance at the ankle and side lying hip abduction (ranging from 81 to 103 % MVIC).

Limitations

The methodological approaches varied between studies, notably in the different positions used for obtaining MVIC, which could have dramatically impacted normalized levels of gluteal activation, while variation also occurred in exercise technique and/or equipment.

Conclusions

The findings from this review provide an indication for the amount of muscle activity generated by basic strengthening and rehabilitation exercises, which may assist practitioners in making decisions for Gmax and Gmed strengthening and injury rehabilitation programs.     

A rat model of hip joint contracture induced by mono-articular hip joint immobilization

BackgroundTo elucidate the formation process and therapeutic targets of hip flexion contracture, we developed a rat model of hip flexion contracture induced by hip mono-articular immobilization.MethodsKirschner wires inserted into the femur and hip bone were anchored at the hip in a flexed position in the immobilization groups and unanchored in the sham groups for up to four weeks. Age-matched untreated rats were used as controls. Hip extension range of motion (RoM) was measured at three different extension moments (7.5, 15, and 22.5 N•mm) in each successive myotomy step as follows: before myotomy, after sequential myotomy of the tensor fascia lata, quadriceps muscle, iliopsoas muscle, and after myotomy of all residual muscles (the gluteus medius and adductor muscles). Histological analysis of the hip joint was also performed.FindingsAfter four weeks of immobilization, the RoM before myotomy at 22.5 N•mm was significantly decreased by 29° compared with controls, and this value was unaltered in the sham group. Analyses following serial myotomy suggested that the structures responsible for myogenic contracture were the tensor fascia lata, iliopsoas, gluteus medius, and adductor muscles because the RoMs were increased by these myotomies. Unexpectedly, arthrogenic contracture was not detected at moments other than at 7.5 N•mm, even after four weeks of immobilization. Histological analysis confirmed that pathological changes were not apparent in the anterior capsule of the hip joint.InterpretationThe present findings suggest that myogenic contracture may be an important therapeutic target for immobilization-induced hip flexion contracture.     

ELECTROMYOGRAPHIC ANALYSIS OF GLUTEUS MEDIUS AND GLUTEUS MAXIMUS DURING REHABILITATION EXERCISES

Purpose/Background:

Previous research studies by Bolga, Ayotte, and Distefano have examined the level of muscle recruitment of the gluteal muscles for various clinical exercises; however, there has been no cross comparison among the top exercises from each study. The purpose of this study is to compare top exercises from these studies as well as several other commonly performed clinical exercises to determine which exercises recruit the gluteal muscles, specifically the gluteus medius and maximus, most effectively.

Methods:

Twenty-six healthy subjects participated in this study. Surface EMG electrodes were placed on gluteus medius and maximus to measure muscle activity during 18 exercises. Maximal voluntary muscle contraction (MVIC) was established for each muscle group in order to express each exercise as a percentage of MVIC and allow standardized comparison across subjects. EMG data were analyzed using a root-mean-square algorithm and smoothed with a 50 millisecond time reference. Rank ordering of the exercises was performed utilizing the average percent MVIC peak activity for each exercise.

Results:

Twenty-four subjects satisfied all eligibility criteria and consented to participate in the research study. Five of the exercises produced greater than 70%MVIC of the gluteus medius muscle. In rank order from highest EMG value to lowest, these exercises were: side plank abduction with dominant leg on bottom (103%MVIC), side plank abduction with dominant leg on top (89%MVIC), single limb squat (82%MVIC), clamshell (hip clam) progression 4 (77%MVIC), and font plank with hip extension (75%MVIC). Five of the exercises recruited gluteus maximus with values greater than 70%MVIC. In rank order from highest EMG value to lowest, these exercises were: front plank with hip extension (106%MVIC), gluteal squeeze (81%MVIC), side plank abduction with dominant leg on top (73%MVIC), side plank abduction with dominant leg on bottom (71%MVIC), and single limb squat (71%MVIC). Four of the exercises produced greater than 70%MVIC for both gluteus maximus and medius muscles.

Conclusions:

Higher %MVIC values achieved during performance of exercises correlate to muscle hypertrophy.^20,22 By knowing the %MVIC of the gluteal musculature that occurs during various exercises, potential for strengthening of the gluteal muscles can be inferred. Additionally, exercises may be rank ordered to appropriately challenge the gluteal musculature during rehabilitation.     

Hip Muscle Activity during Isometric Contraction of Hip Abduction

[Purpose] This study aimed to determine the effect of varying hip flexion angle on hip muscle activity during isometric contraction in abduction. [Subjects] Twenty-seven healthy men (mean age=21.5 years, SD=1.2) participated in this study. [Methods] Surface electromyography (EMG) was recorded of the upper portion of the gluteus maximus (UGM), lower portion of the gluteus maximus (LGM), tensor fasciae latae (TFL), and gluteus medius (GMed) during isometric contraction under two measurement conditions: hip flexion angle (0, 20, 40, 60, and 80 degrees) and abduction of the hip joint at 20, 40, 60, and 80% maximum strength. Integrated EMG (IEMG) were calculated and normalized to the value of maximum voluntary contraction (MVC). [Results] Results indicated that the IEMG of both the UGM and LGM increased significantly with increases in hip flexion angle, whereas the IEMG of the TFL decreased significantly. The maximum activities of the UGM and the LGM were 85.7 ± 80.8%MVC and 38.2 ± 32.9%MVC at 80 degrees of hip flexion, respectively, and that of the TFL was 71.0 ± 39.0%MVC at 40 degrees of hip flexion. [Conclusion] The IEMG of the GMed did not change with increases in hip flexion angle. Hip flexion angle affected the activity of the GM and TFL during isometric contraction in abduction.Key words: Hip abductor, Electromyography, Muscle activity     

Comparison between side-lying and standing positions for hip abductor strength assessment

BackgroundThe hip abductor muscles control the pelvis in the frontal plane and allow the maintenance of trunk position and dynamic balance during weight-bearing activities.ObjectiveTo compare the side-lying and standing positions for hip abductor strength assessment with regards to torque production and myolectric activity.MethodConcentric and eccentric hip abductor peak torque and total work, and myoelectric activity of the tensor fascia lata, gluteus medius, and inferior and superior portions of the gluteus maximus muscles were measured during maximal isokinetic tests for hip abductor strength in the side-lying and standing positions. The Wilcoxon test was used to compare variables between the positions.ResultsPeak torque values did not differ between side-lying and standing positions for both concentric and eccentric contraction modes (p > .05). During standing position, greater concentric total work was observed (p = .013). This position resulted in a lower activity of the tensor fascia lata muscle (p = .005) compared to side lying position. Myoelectric activity of gluteus medius, and inferior and superior portions of the gluteus maximus was similar between positions (p > .05).ConclusionBoth positions presented similar peak torque values and, during the standing position, a greater concentric total work and lesser activation of the tensor fascia lata was observed. Standing position can be used when emphasis on the superior portion of gluteus maximus over the tensor fascia lata is intended.     

Relative electromyographic activity in trunk,hip, and knee muscles during unilateral weight bearing exercises: Implications for rehabilitation

Background: Clinicians routinely prescribe unilateral weight bearing exercises to strengthen the lower extremity. Researchers have primarily examined thigh muscle activation with minimal attention to the hip and trunk muscles. The purpose of this study was to quantify trunk, hip, and thigh muscle activation during these types of exercises. Methods: Electromyographic (EMG) activity was collected for the abdominal obliques (AO), lumbar extensors (LE), gluteus maximus (GMX), gluteus medius (GM), and vastus medialis (VM) as subjects performed four unilateral weight bearing exercises. Data were expressed as 100% of a maximum voluntary isometric contraction (% MVIC). Separate analyses of variance with repeated measures were used to identify muscle activity differences across exercise. The sequentially-rejective Bonferroni test was used for all post-hoc analyses. Results: EMG activity for the AO, LE, and GMX was low (5.7–18.9% MVIC) during all the exercises. The GM activity was moderate (21.4–26.5% MVIC) while VM activity was high (40.0–45.2% MVIC). Conclusion: Lower AO and LE activation most likely resulted from subjects maintaining a vertical trunk position over the stance limb during each exercise. The fact that the exercises required greater frontal plane control (from balancing on a single limb) most likely accounted for lower GMX activity. The exercises would provide little, if any, benefit for individuals with AO, LE, or GMX weakness. The unilateral weight bearing exercises would be beneficial for GM neuromuscular re-education and endurance and VM strengthening.     

Effects of Tibiofibular and Ankle Joint Manipulation on Hip Strength and Muscle Activation

ObjectivesThe purpose of this study was to determine whether high-velocity, low-amplitude ankle region manipulations could increase force output and muscle activation of hip musculature in individuals with a history of ankle sprain and unilateral tensor fascia latae (TFL) weakness during muscle testing.MethodsThis investigation used a single-arm repeated measures design. Twenty-five participants’ force outputs were tested at three time points (before manipulation, immediately after manipulation, and 48 hours after manipulation), and muscle activation of the rectus femoris, gluteus medius, and TFL was measured before and immediately after manipulation. Manipulations were applied to the talocrural, subtalar, proximal, and distal tibiofibular joints of the weaker limb. No contralateral manipulations were applied. Two-way repeated measures analysis of variance was used to compare maximal and average force production for each limb. In addition, paired t tests were used to compare muscle activation before and after manipulations.ResultsThere was a significant limb × time interaction. The involved limb average force increased from before manipulation (65.7 N) to 48 hours after manipulation (77.8 N; P = .014), maximal force increased (76.9 N) 48 hours after manipulation (87.8 N; P = .030), and gluteus medius activation increased (9.8% maximum, 12.2% average) immediately after manipulation. No significant differences were found in the uninvolved limb.ConclusionThe results of this study suggest that high-velocity, low-amplitude ankle region manipulations might improve hip abductor strength in individuals with a history of ankle sprain and unilateral weakness during a TFL muscle test.     

The relationship between gluteus medius latent trigger point and muscle strength in healthy subjects

IntroductionWe hypothesized that latent MTrPs might decrease gluteus medius muscle strength in healthy individuals. This study aimed to investigate the relationship between latent MTrPs and gluteus medius muscle strength in a group of healthy adults.MethodsForty-eight healthy men were included in the study. Trigger point examination for the gluteus medius was performed bilaterally. Subjects with one or more trigger points on the dominant side and those without any trigger point were assigned to two groups. Muscle strength for the gluteus medius was assessed with a manual muscle tester using the “break test” technique on both sides. For statistical analysis, the independent sample t-test was used to compare the intergroup differences.ResultsThe latent MTrP group demonstrated lower abduction muscle strength in the dominant gluteus medius. Moreover, the latent MTrP group showed higher abduction muscle strength in the non-dominant gluteus medius (p < 0.05). Intergroup comparison revealed that gluteus medius abduction muscle strength on the dominant side was higher in the non-latent MTrP group (p < 0.05).ConclusionLatent MTrP may cause joint movement limitation, overload by affecting motor activation patterns and reciprocal inhibition mechanisms. Outcomes of the current study revealed that gluteus medius abduction strength values below 9.7 kg could be associated with latent MTrP with high sensitivity and low specificity. It is imperative to note that the latent MTrP of gluteus medius muscle, which has a critical role in the lumbopelvic junction, should not be ignored in clinical practice, and treatment should be applied when detected.     

No Difference in Hip Muscle Volumes and Fatty Infiltration in Those With Hip-Related Pain Compared to Controls

BackgroundLittle is known about muscle morphology in people with hip-related pain, without signs of femoro-acetabular impingement syndrome (FAIS). Identifying changes in hip muscle volume, fatty infiltrate and establishing relationships between muscle volume and strength, may provide insight into potential early treatment strategies.PurposesTo: (i) compare the volumes and fatty infiltrate of gluteus maximus, gluteus medius, gluteus minimis, tensor fascia latae and quadratus femoris between symptomatic and less-symptomatic sides of participants with hip-related pain; (ii) compare the volumes and fatty infiltrate of hip muscles between healthy controls and symptomatic participants; and (iii) explore relationships of hip muscle volumes to muscle strength and patient-reported outcome measures in people with hip-related pain.Study DesignCross-sectional studyMethodsMuscle volume and fatty infiltrate (from magnetic resonance imaging), hip muscle strength, patient-reported symptoms, function and quality of life (QOL) were determined for 16 participants with hip-related pain (no clinical signs of FAIS; 37±9 years) and 15 controls (31±9 years). Using One Way Analysis of Co-Variance tests, muscle volume and fatty infiltrate was compared between the symptomatic and less-symptomatic sides in participants with hip-related pain as well as between healthy controls and symptomatic participants. In addition, hip muscle volume was correlated with hip muscle strength, hip-reported symptoms, function and QOL.ResultsNo differences in all the studied muscle volumes or fatty infiltrate were identified between the symptomatic and less-symptomatic hips of people with hip-related pain; or between people with and without hip-related pain. Greater GMED volume on the symptomatic side was associated with less symptoms and better function and QOL (ρ=0.522-0.617) for those with hip-related pain. Larger GMAX volume was associated with greater hip abduction and internal rotation strength, larger GMED volume was associated with greater hip extension strength, and larger QF volume was associated with greater hip abduction strength (rho=0.507-0.638).ConclusionPeople with hip-related pain and no clinical signs of FAIS have hip muscle volumes that are not significantly different than those of matched pain-free controls or their less-symptomatic hip. Larger GMED muscle volume was associated with fewer symptoms and greater strength.Level of evidenceLevel 3a     

Influence of Hip Joint Position on Muscle Activity during Prone Hip Extension with Knee Flexion

[Purpose] This study investigated the selective activation of the gluteus maximus during a prone hip extension with knee flexion exercise, with the hip joint in different positions. [Subjects] The subjects were 21 healthy, male volunteers. [Methods] Activities of the right gluteus maximus, right hamstrings, bilateral lumbar erector spinae, and bilateral lumbar multifidus were measured using surface electromyography during a prone hip extension with knee flexion exercise. Measurements were made with the hip joint in each of 3 positions: (1) a neutral hip joint position, (2) an abduction hip joint position, and (3) an abduction with external rotation hip joint position. [Results] Gluteus maximus activity was significantly higher when the hip was in the abduction with external rotation hip joint position than when it was in the neutral hip joint and abduction hip joint positions. Gluteus maximus activity was also significantly higher in the abduction hip joint position than in the neutral hip joint position. Hamstring activity was significantly lower when the hip was in the abduction with external rotation hip joint position than when it was in the neutral hip joint and abduction hip joint positions. [Conclusion] Abduction and external rotation of the hip during prone hip extension with knee flexion exercise selectively activates the gluteus maximus.Key words: Prone hip extension with knee flexion, Hip joint position, Electromyography     

HIP MUSCLE ACTIVATION AND KNEE FRONTAL PLANE MOTION DURING WEIGHT BEARING THERAPEUTIC EXERCISES

Purpose/Background:

Hip abduction strengthening exercises may be critical in the prevention and rehabilitation of both overuse and traumatic injuries where knee frontal plane alignment is considered to be important. The purpose of the current investigation was to examine the muscular activation of the gluteus maximus and gluteus medius during the double-leg squat (DLS), single-leg squat (SLS), or front step-up (FSU), and the same exercises when an added load was used to pull the knee medially.

Methods:

Eighteen healthy females (ages 18-26) performed six exercises: DLS, DLS with load, FSU, FSU with load, SLS, and SLS with load. Integrated and peak surface electromyography of gluteus maximus and gluteus medius of the dominant leg were recorded and normalized. Motion analysis was used to measure knee abduction angle during each exercise.

Results:

SLS had the highest integrated and peak activation for both muscles, regardless of load. Adding load, only increased DLS integrated gluteus maximus activation (p=0.019). Load did not increase integrated gluteus medius or peak gluteus maximus activation. Adding load decreased SLS peak gluteus medius activation (p=0.003). Adding load increased peak knee abduction angle during DLS (p=0.013), FSU (p=0.000), and SLS (p=0.011).

Conclusions:

Overall, the SLS was most effective exercise for activating the gluteus maximus and gluteus medius. Applied knee load does not appear to increase muscle activation during SLS and FSU. DLS with an applied load may be more beneficial in activating the gluteus maximus. Overall, the use of applied loads appears to promote poorer musculoskeletal alignment in terms of peak knee valgus angle.Level of Evidence: 3     

Effect of abduction and external rotation of the hip joint on muscle onset time during prone hip extension with knee flexion

[Purpose] This study investigated the effect of hip position on muscle onset time during prone hip extension with knee flexion. [Subjects] The study included 21 healthy male volunteers. [Methods] Muscle onset times of the right gluteus maximus, right hamstrings, bilateral lumbar erector spinae, and bilateral lumbar multifidus were measured using surface electromyography during right hip extension with knee flexion in the prone position. Measurements were made with the hip in 3 positions: (1) neutral, (2) abduction, and (3) abduction and external rotation. [Results] Gluteus maximus onset relative to the hamstrings was significantly earlier with hip abduction and with hip abduction and external rotation compared with that with the hip in the neutral position. Gluteus maximus onset relative to the hamstrings was significantly earlier with hip abduction and external rotation compared with that with hip abduction. The bilateral multifidus and left lumbar erector spinae onset times relative to the hamstrings were significantly earlier with hip abduction and external rotation compared with those with hip abduction and with the hip in the neutral position. [Conclusion] Abduction and external rotation of the hip during prone hip extension with knee flexion is effective for advancing the onset times of the gluteus maximus, bilateral multifidus, and contralateral lumbar erector spinae.Key words: Prone hip extension with knee flexion, Hip joint position, Muscle onset time     

Comparison of the gluteus medius and rectus femoris muscle activities during natural sit-to-stand and sit-to-stand with hip abduction in young and older adults

[Purpose] The purpose of this study was to compare the relative levels of activation of the gluteus medius (Gmed) and rectus femoris (RF) muscles during natural (N) sit-to-stand (STS) and STS with hip abduction (ABD) in young and elderly females. [Subjects] We recruited 15 healthy young females and 15 healthy elderly females. [Methods] The activities of the dominant lower extremity gluteus medius (Gmed) and rectus femoris (RF) muscles were measured using a wireless electromyography (EMG) system for natural STS and STS with hip abduction. [Result] In the elderly subjects, the Gmed increased significantly and RF decreased significantly when STS was performed with hip ABD compared with when it was performed naturally. The Gmed in the elderly subjects was significantly increased during natural STS compared with in the young subjects. [Conclusion] These results indicate that the Gmed was recruited to compensate for weakened RF muscle function in the elderly adults.Key words: Gluteus medius, Sit-to-stand, Hip abduction     

Gluteal muscle dysfunction and the role of specific strengthening in hip osteoarthritis: a review

Abstract

Background: The muscle system provides essential support to a joint, and muscle weakness and atrophy may occur in the presence of joint pathology, such as osteoarthritis (OA). The gluteal muscles – gluteus medius and gluteus maximus – provide an important stability role in the hip joint and evidence exists for gluteal weakness in hip OA. Therefore, rehabilitation should address such dysfunction.

Objectives: To identify the use of gluteal strengthening in exercise-based randomised controlled trials or randomised clinical trials of hip OA.

Methods: A structured literature search was undertaken to review the evidence for use of gluteal strengthening in hip OA clinical trials.

Results: Eleven randomised controlled or randomised clinical trials of strengthening-based exercise in hip OA were identified and searched for evidence of gluteal strengthening. None of the studies reported specific strengthening of the gluteal muscles and details of the strengthening regimes used were poorly described in most of the studies. This lack of specificity may be one of the reasons why only small effect sizes and short-term benefits have been found for exercise therapy in the management of hip OA.     

Comparison of gluteus medius muscle activity during functional tasks in individuals with and without osteoarthritis of the hip joint

Background

Neuromuscular alterations have been reported for patients with osteoarthritis of the hip joint; however, the underlying cause associated with altered gluteus medius muscle function has not been examined. This study assessed electromyographic amplitudes of the gluteus medius muscles during function in patients with unilateral end-stage osteoarthritis of the hip joint compared to controls.

Methods

Patients with unilateral end-stage hip joint osteoarthritis (n = 13) and asymptomatic control participants (n = 17) participated. Average root-mean squared muscle amplitudes represented as a percent of maximum voluntary isometric contraction for both the involved and uninvolved limb gluteus medius muscles were analyzed during step up, step down, and gait. The association between muscle activation and impact forces during stepping tasks was assessed.

Findings

Patients with hip osteoarthritis exhibited increased gluteus medius muscle electromyographic amplitudes bilaterally during stair ascent, stair descent, and gait compared to controls, regardless of which limb they led. Involved limb muscle activity was inversely related to impact force during step down onto the ipsilateral limb.

Interpretation

Patients with hip osteoarthritis demonstrated increased gluteus medius muscle activation levels during stepping tasks and gait when compared to controls. The increased activation is most likely a compensatory response to muscle weakness. Therefore, application of strengthening exercises which target the gluteal muscles should assist in neuromuscular control and result in improved strength for patients with hip joint osteoarthritis.