Femoral anteversion influences vastus medialis and gluteus medius EMG amplitude: composite hip abductor EMG amplitude ratios during isometric combined hip abduction-external rotation.

This prospective study evaluated differences in vastus medialis (VM) and gluteus medius (GM) EMG amplitude:composite hip abductor (gluteus maximus, gluteus medius, tensor fascia lata) EMG amplitude ratios among subjects with low or high relative femoral anteversion. Data were collected during the performance of a non-weight bearing, non-sagittal plane maximal volitional effort isometric combined hip abduction-external rotation maneuver. Eighteen nonimpaired athletically active females participated in this surface EMG study. Medial hip rotation (relative femoral anteversion estimate) was measured with a handheld goniometer. Subjects were grouped by medial hip rotation displacement (group 1 < or = 42 degrees =36.1+/-7 degrees and group 2 > 42 degrees =52.7+/-7 degrees ) for statistical analysis (Mann Whitney U-tests, p < 0.05). Group 2 had decreased VM (42+/-23% vs. 69+/-30%, U=19, p=0.034) and GM (62+/-25% vs. 96+/-39%, U=19, p=0.034) normalized mean peak EMG amplitude:composite mean peak hip abductor EMG amplitude ratios compared to group 1. Decreased normalized VM (-27%) and GM (-34%) EMG amplitudes among subjects with increased relative femoral anteversion suggest reduced dynamic frontal and transverse plane femoral control from these muscles, possibly contributing to the increased incidence of non-contact knee injury observed among athletic females.     

Reliability of surface electromyography for the gluteus medius muscle during gait in people with and without chronic nonspecific low back pain

The purpose of this study was to determine the intratester reliability of surface electromyography (EMG) assessment of the gluteus medius muscle in healthy people and people with chronic nonspecific low back pain (CNLBP) during barefoot walking. Gluteus medius muscle activity was measured twice in 40 people without and 30 people with CNLBP approximately 7 days apart. Walking gluteus medius muscle activity was normalised to maximal voluntary isometric contractions during side-lying hip abduction with manual resistance. Good intratester reliability (ICC > 0.75) was found for mean, peak, and peak to peak amplitude for healthy people. Only mean amplitude demonstrated good intratester reliability in those with CNLBP. Peak amplitude and peak to peak amplitude of the gluteus medius muscle of those with CNLBP, and the time of peak amplitude in both groups, demonstrated moderate reliability (ICC ranged from 0.50 to 0.58). Moderate to large standard error of measurement and minimal detectable change values were reported for outcome measurements. These results suggest that potentially large levels of random error can occur between sessions. Future research can build on this study for those with pathology and attempt to establish change values for EMG that are clinically meaningful.     

A comparison of surface and fine wire EMG recordings of gluteus medius during selected maximum isometric voluntary contractions of the hip

Electromyographic (EMG) studies into gluteus medius (GMed) typically involve surface EMG electrodes. Previous comparisons of surface and fine wire electrode recordings in other muscles during high load isometric tasks suggest that recordings between electrodes are comparable when the muscle is contracting at a high intensity, however, surface electrodes record additional activity when the muscle is contracting at a low intensity. The purpose of this study was to compare surface and fine wire recordings of GMed at high and low intensities of muscle contractions, under high load conditions (maximum voluntary isometric contractions, MVICs). Mann–Whitney U tests compared median electrode recordings during three MVIC hip actions; abduction, internal rotation and external rotation, in nine healthy adults. There were no significant differences between electrode recordings in positions that evoked a high intensity contraction (internal rotation and abduction, fine wire activity >77% MVIC; effect size, ES < 0.42; p > 0.277). During external rotation, the intensity of muscle activity was low (4.2% MVIC), and surface electrodes recorded additional myoelectric activity (ES = 0.67, p = 0.002). At low levels of muscle activity during high load isometric tasks, the use of surface electrodes may result in additional myoelectric recordings of GMed, potentially reflective of cross-talk from surrounding muscles.     

The influence of hip strength on gluteal activity and lower extremity kinematics

The effects of hip muscle strength and activation on anterior cruciate ligament injury biomechanics, particularly knee valgus loading, have been reported in isolation and with equivocal results. However, the combination of these factors influences joint biomechanics. This investigation evaluated the influence of hip strength on gluteal activation and knee valgus motion. Maximal isometric hip abduction (ABD) and external rotation (ER) contractions were used to define High and Low strength groups. Knee kinematics and gluteus maximus (GMax) and medius (GMed) EMG amplitudes obtained during landing were compared between High and Low strength groups after controlling for the potential confounding influence of sex. Knee valgus motion did not differ between the High and Low hip ABD and ER strength groups. However, the Low ABD and ER strength groups displayed greater GMed and GMax EMG amplitudes, respectively, compared to the High strength groups. These findings suggest that weaker individuals compensate for a lack of force production via heightened neural drive. As such, hip muscle strength influences knee valgus motion indirectly by determining neural drive requirements.     

Insight into the function of the obturator internus muscle in humans: Observations with development and validation of an electromyography recording technique

There are no direct recordings of obturator internus muscle activity in humans because of difficult access for electromyography (EMG) electrodes. Functions attributed to this muscle are based on speculation and include hip external rotation/abduction, and a role in stabilization as an “adjustable ligament” of the hip. Here we present (1) a technique to insert intramuscular EMG electrodes into obturator internus plus (2) the results of an investigation of obturator internus activity relative to that of nearby hip muscles during voluntary hip efforts in two hip positions and a weight-bearing task. Fine-wire electrodes were inserted with ultrasound guidance into obturator internus, gluteus maximus, piriformis and quadratus femoris in ten participants. Participants performed ramped and maximal isometric hip efforts (open kinetic chain) into flexion/extension, abduction/adduction, and internal/external rotation, and hip rotation to end range in standing. Analysis of the relationship between activity of the obturator internus and the other hip muscles provided evidence of limited contamination of the recordings with crosstalk. Obturator internus EMG amplitude was greatest during hip extension, then external rotation then abduction, with minimal to no activation in other directions. Obturator internus EMG was more commonly the first muscle active during abduction and external rotation than other muscles. This study describes a viable and valid technique to record obturator internus EMG and provides the first evidence of its activation during simple functions. The observation of specificity of activation to certain force directions questions the hypothesis of a general role in hip stabilisation regardless of force direction.     

Test–retest reliability of cardinal plane isokinetic hip torque and EMG

The objective of the present study was to establish test–retest reliability of isokinetic hip torque and prime mover electromyogram (EMG) through the three cardinal planes of motion. Thirteen healthy young adults participated in two experimental sessions, separated by approximately one week. During each session, isokinetic hip torque was evaluated on the Biodex Isokinetic Dynamometer at a velocity of 60 deg/s. Subjects performed three maximal-effort concentric and eccentric contractions, separately, for right and left hip abduction/adduction, flexion/extension, and internal/external rotation. Surface EMGs were sampled from the gluteus maximus, gluteus medius, adductor, medial and lateral hamstring, and rectus femoris muscles during all contractions. Intraclass correlation coefficients (ICC – 2,1) and standard errors of measurement (SEM) were calculated for peak torque for each movement direction and contraction mode, while ICCs were only computed for the EMG data. Motions that demonstrated high torque reliability included concentric hip abduction (right and left), flexion (right and left), extension (right) and internal rotation (right and left), and eccentric hip abduction (left), adduction (left), flexion (right), and extension (right and left) (ICC range = 0.81–0.91). Motions with moderate torque reliability included concentric hip adduction (right), extension (left), internal rotation (left), and external rotation (right), and eccentric hip abduction and adduction (right), flexion (left), internal rotation (right and left), and external rotation (right and left) (ICC range = 0.49–0.79). The majority of the EMG sampled muscles (n = 12 and n = 11 for concentric and eccentric contractions, respectively) demonstrated high reliability (ICC = 0.81–0.95). Instances of low, or unacceptable, EMG reliability values occurred for the medial hamstring muscle of the left leg (both contraction modes) and the adductor muscle of the right leg during eccentric internal rotation. The major finding revealed high and moderate levels of between-day reliability of isokinetic hip peak torque and prime mover EMG. It is recommended that the day-to-day variability estimates concomitant with acceptable levels of reliability be considered when attempting to objectify intervention effects on hip muscle performance.     

Does gender influence neuromotor control of the knee and hip?

Patellofemoral pain (PFP) is a common condition that occurs more frequently in females. Anatomical, hormonal and neuromuscular factors have been proposed to contribute to the increased incidence of PFP in females, with neuromuscular factors considered to be of particular importance. This cross-sectional study aimed to evaluate differences in the neuromotor control of the knee and hip muscles between genders and to investigate whether clinical measures of hip rotation range and strength were associated with EMG measures of hip and thigh motor control. Twenty-nine (16 female and 13 male) asymptomatic participants completed a visual choice reaction-time stair stepping task. EMG activity was recorded from vastus medialis oblique, vastus lateralis, anterior and posterior gluteus medius muscles. In addition hip rotation range of motion and hip external rotation, abduction and trunk strength were assessed. There were no differences in the timing or peak of EMG activation of the vasti or gluteus medius muscle between genders during the stepping task. There were however significant associations between EMG measures of motor control of the vasti and hip strength in both females and males. These findings are suggestive of a link between hip muscle control and vasti neuromotor control.     

Variation of rotation moment arms with hip flexion.

Excessive flexion and internal rotation of the hip is a common gait abnormality among individuals with cerebral palsy. The purpose of this study was to examine the influence of hip flexion on the rotational moment arms of the hip muscles. We hypothesized that flexion of the hip would increase internal rotation moment arms and decrease external rotation moment arms of the primary hip rotators. To test this hypothesis we measured rotational moment arms of the gluteus maximus (six compartments), gluteus medius (four compartments), gluteus minimus (three compartments) iliopsoas, piriformis, quadratus femoris, obturator internus, and obturator externus. Moment arms were measured at hip flexion angles of 0, 20, 45, 60, and 90 degrees in four cadavers. A three-dimensional computer model of the hip muscles was developed and compared to the experimental measurements. The experimental results and the computer model showed that the internal rotation moment arms of some muscles increase with flexion; the external rotation moment arms of other muscles decrease, and some muscles switch from external rotation to internal rotation as the hip is flexed. This trend toward internal rotation with hip flexion was apparent in 15 of the 18 muscle compartments we examined, suggesting that excessive hip flexion may exacerbate internal rotation of the hip. The gluteus maximus was found to have a large capacity for external rotation. Enhancing the activation of the gluteus maximus, a muscle that is frequently underactive in persons with cerebral palsy, may help correct excessive flexion and internal rotation of the hip.     

Activation of the VMO and VL during dynamic mini-squat exercises with and without isometric hip adduction

Objective: the purpose of this study was to compare vastus medialis obliquus (VMO) and vastus lateralis (VL) activity while performing a mini-squat with and without isometric hip adduction.

Design and setting: a repeated measures within subjects design was used. Subjects performed two sets of three repetitions of a traditional mini-squat and a mini-squat with concurrent hip adduction (squeeze).

Subjects: 20 recreationally active subjects (10 men, 10 women AGE=28.10±5.91 years, HEIGHT=170.94±11.03 cm, MASS=72.32±16.66 kg) with no history of patellofemoral pain (PFP), quadriceps injury, or other knee injury participated in the study.

Measurements: the EMG signal of the VMO and VL was recorded bilaterally during both exercises. EMG data were normalized to the maximal voluntary isometric contraction (MVIC) of the quadriceps produced during seated, isometric knee extension.

Results: results of repeated measures ANOVA's revealed that the squeeze squat produced significantly greater VMO and VL activity than the traditional squat (p=0.02). For both the traditional and squeeze squats, intrasession reliability from the first to the second set was calculated using intraclass correlation coefficient (ICC) formula (3:1) bilaterally for both the VMO and the VL. All ICC values were greater than 0.9.

Conclusion: combining isometric hip adduction with a mini-squat exercise significantly increases the activity of the quadriceps. Performing mini-squats with isometric hip adduction will be beneficial to patellofemoral patients as they increase quadriceps activity, however, based on our data we cannot conclude that this exercise preferentially recruits the VMO. Further research is needed to determine the exact mechanism by which quadriceps function is altered.     

The effects of whole-body vibration on EMG activity of the lower body muscles in supine static bridge position

Objectives:The purpose of the current study was to firstly examine the effects of different whole-body vibration (WBV) frequencies in the lower-body muscles when applied simultaneously during a bridge exercise. Secondly, determine if there were any sex differences in the lower-body muscles of WBV during the bridge.Methods:Seven females and 7 males completed 2 familiarization and 1 test sessions. In the test session participants were randomized to complete one 30 s bout of a bridge exercise for 3 separate condition s followed by 3-min of rest. The 3 conditions (a) No-WBV (without WBV); (b) WBV-30 (30 Hz, low amplitude); (c) WBV-50 (50 Hz, low amplitude) were performed on a WBV platform. Muscle activity of the biceps femoris (BF), semitendinosus (ST), gluteus maximus (Gmax), multifidus muscle (MF) muscles were measured.Results:Muscle activity was increased with WBV in the BF and ST muscles at WBV-30 and WBV-50 conditions (p<0.05) vs. no-WBV. During No-WBV and WBV-50 conditions, males had a higher biceps femoris activity compared to females for (p<0.05) 45 and 27 %, respectively; however, during all conditions females had a high level of Gmax activity (57%) than males (p<0.05).Conclusion:Additional vibration at 30 and 50 Hz during the bridge exercise could be a useful method to enhance hamstring muscle activity.     

Experimentally reduced hip abductor function during walking: Implications for knee joint loads

Hip and knee functions are intimately connected and reduced hip abductor function might play a role in development of knee osteoarthritis (OA) by increasing the external knee adduction moment during walking. The purpose of this study was to test the hypothesis that reduced function of the gluteus medius (GM) muscle would lead to increased external knee adduction moment during level walking in healthy subjects. Reduced GM muscle function was induced experimentally, by means of intramuscular injections of hypertonic saline that produced an intense short-term muscle pain and reduced muscle function. Isotonic saline injections were used as non-painful control. Fifteen healthy subjects performed walking trials at their self-selected walking speed before and immediately after injections, and again after 20 min of rest, to ensure pain recovery. Standard gait analyses were used to calculate three-dimensional trunk and lower extremity joint kinematics and kinetics. Surface electromyography (EMG) of the glutei, quadriceps, and hamstring muscles were also measured. The peak GM EMG activity had temporal concurrence with peaks in frontal plane moments at both hip and knee joints. The EMG activity in the GM muscle was significantly reduced by pain (?39.6%). All other muscles were unaffected. Peaks in the frontal plane hip and knee joint moments were significantly reduced during pain (?6.4% and ?4.2%, respectively). Lateral trunk lean angles and midstance hip joint adduction and knee joint extension angles were reduced by ?1°. Thus, the gait changes were primarily caused by reduced GM function. Walking with impaired GM muscle function due to pain significantly reduced the external knee adduction moment. This study challenge the notion that reduced GM function due to pain would lead to increased loads at the knee joint during level walking.     

Reliability of electromyographic normalization methods for evaluating the hip musculature.

The purpose of this study was to determine the reliability of three normalization methods for analyzing hip abductor activation during rehabilitation exercises. Thirteen healthy subjects performed three open kinetic chain and three closed kinetic chain hip abductor exercises. Surface EMG activity for the gluteus medius was collected during each exercise and normalized based on a maximum voluntary isometric contraction (MVIC), mean dynamic (m-DYN), and peak dynamic activity (pk-DYN). Intraclass coefficient correlations (ICCs), intersubject coefficients of variation (CVs), and intrasubject CVs were then calculated for each normalization method. MVIC ICCs exceeded 0.93 for all exercises. M-DYN and pk-DYN ICCs exceeded 0.85 for all exercises except for the sidelying abduction exercise. Intersubject CVs ranged from 55% to 77% and 19% to 61% for the MVIC and dynamic methods, respectively. Intrasubject CVs ranged from 11% to 22% for all exercises under all normalization methods. The MVIC method provided the highest measurement reliability for determining differences in activation amplitudes between hip abductor exercises in healthy subjects. Future research should determine if these same results would apply to a symptomatic patient population.     

Statistical modelling of fatigue-related electromyographic median frequency characteristics of back and hip muscles during a standardized isometric back extension test.

The purpose of the present study was to evaluate which statistical model - linear, logarithmic, quadratic or exponential - best described the fatigue-related electromyographic (EMG) changes of back and hip muscles. Twenty healthy volunteers performed a modified Biering-Sorensen test. The EMG activity of the latissimus dorsi (LD), longissimus thoracis pars thoracis (LTT) and lumborum (LTL), iliocostalis lumborum pars thoracis (ILT) and lumborum (ILL), multifidus (MF), gluteus maximus (GM) and biceps femoris (BF) was measured bilaterally using surface electrodes. Higher R(2) values were found for the quadratic models (p<0.05 for all muscles), and lower R(2) values for the logarithmic models (p<0.05 for LTT, LTL, ILL, MF and GM). The exponential models generated higher R(2) values compared to the linear ones for the LTT, LTL and MF (all p<0.05). Further analyses revealed, however, that these models did not add useful additional information, and therefore would only increase the complexity. The findings of the current study validate the use of simple linear regression techniques when studying fatigue-related EMG median frequency characteristics of back and hip muscles during isometric contractions.     

Pelvic instability and trunk and hip muscle recruitment patterns in patients with total hip arthroplasty

Hip and lumbar spine disorders often coexist in patients with total hip arthroplasty (THA). The current study aimed to reveal pelvic motion pathology and altered trunk and hip muscle recruitment patterns relating to pelvic motion in patients with THA. Twenty-one women who underwent THA and 12 age-matched healthy women were recruited. Pelvic kinematics and muscle recruitment patterns (i.e., amplitude, activity balance, and onset timing) of the gluteus maximus, semitendinosus, multifidus, and erector spinae were collected during prone hip extension. Compared with healthy subjects, the patients showed increased pelvic motion, especially ventral rotation, decreased multifidus muscle activity relative to the hip extensors, and delayed onset of multifidus activity, despite reaction times and speeds of leg motion not being significantly different between the groups. Furthermore, while contributing factors associated with ventral pelvic rotation were not found, delayed onset of multifidus activity was detected as a factor related to the increased anterior tilt of the pelvis (r = 0.47, p < 0.05) in patients with THA. These results suggest that patients with THA have dysfunction of the stabilizer muscles of the lumbopelvic region along with increased pelvic motion.     

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.     

Superimposing hip extension on knee flexion evokes higher activation in biceps femoris than knee flexion alone

Hamstring muscle function during knee flexion has been linked to hamstring injury and performance. However, it is unclear whether knee flexion alone (KF) requires similar hamstring electromyography (EMG) activity pattern to simultaneous hip extension and knee flexion (HE-KF), a combination that occurs in the late swing phase of sprinting. This study examined whether HE-KF maximal voluntary isometric contraction (MVIC) evokes higher (EMG) activity in biceps femoris long head (BFlh) and semitendinosus (ST) than KF alone. Effects of shank rotation angles were also tested. Twenty-one males performed the above-mentioned MVICs while EMG activity was measured along ST and BFlh. Conditions were compared using a one-way mixed functional ANOVA model under a fully Bayesian framework. Higher EMG activity was found in HE-KF in all shank rotation positions than in KF in the middle region of BFlh (highest in the 9th channel, by 0.022 mV [95%CrI 0.014 to 0.030] in neutral shank position). For ST, this was only observed in the neutral shank position and in the most proximal channel (by 0.013 mV [95%CrI 0.001 to 0.025]). We observed muscle- and region-specific responses to HE-KF. Future studies should examine whether hamstring activation in this task is related to injury risk and sprint performance.     

Gluteus medius: An intramuscular EMG investigation of anterior,middle and posterior segments during gait

Previous electromyographic (EMG) studies of gluteus medius (GMed) have not accurately quantified the function of the three proposed structurally and functionally unique segments (anterior, middle and posterior). Therefore this study used anatomically verified locations for intramuscular electrode recordings in three segments of GMed to determine whether the segments are functionally independent. Bipolar fine wire electrodes were inserted into each segment of GMed in 15 healthy individuals. Participants completed a series of four walking trials, followed by maximum voluntary isometric contractions (MVICs) in five different positions. Temporal and amplitude variables for each segment were compared across the gait cycle using ANOVA. The relative contributions of each segment to the MVIC trials were compared with non-parametric tests. All segments showed a biphasic response during the stance phase of gait. There were no differences in amplitude variables (% MVIC) between segments, but the anterior segment had a later peak during both the first and second bursts. For the MVIC trials, there were significant differences in amplitude between segments in four of the five test positions. These data indicate that GMed is composed of three functionally independent segments. This study contributes to the theoretical understanding of the role of GMed.     

Effect of isometric horizontal abduction on pectoralis major and serratus anterior EMG activity during three exercises in subjects with scapular winging

The aim of this study was to determine the effect of isometric horizontal abduction using Thera-Band during three exercises (forward flexion, scaption, and wall push-up plus) in subjects with scapular winging by investigating the electromyographic (EMG) amplitude of the pectoralis major, serratus anterior and the pectoralis major/serratus anterior activity ratio. Twenty-four males with scapular winging participated in this study. The subjects performed the forward flexion, scaption, and wall push-up plus with and without isometric horizontal abduction using Thera-Band. Surface EMG was used to collect the EMG data of the pectoralis major and serratus anterior during the three exercises. Two-way repeated analyses of variance with two within-subject factors (isometric horizontal abduction condition and exercise type) were used to determine the statistical significance of pectoralis major and serratus anterior EMG activity and the pectoralis major/serratus anterior EMG activity ratio. Pectoralis major EMG activity was significantly lower during forward flexion and wall push-up plus with isometric horizontal abduction, and serratus anterior EMG activity was significantly greater with isometric horizontal abduction. Additionally, the pectoralis major/serratus anterior activity ratio was significantly lower during the forward flexion and wall push-up plus with isometric horizontal abduction. The results of this study suggest that isometric horizontal abduction using Thera-Band can be used as an effective method to facilitate the serratus anterior activity and to reduce excessive pectoralis major activity during exercises for activating serratus anterior.     

On the errors in assessment of severity of involuntary movements using surface EMG.

Surface electromyogram (SEMG) is a useful tool to depict involuntary movements, but evaluation of the intensity of such movements with SEMG over multiple recording instances requires awareness of factors influencing quantified SEMG signals. We investigated the differences in the amplitude of SEMGs due to electrode displacement in isometric voluntary contraction in the upper arm, forearm and lower leg in 8 healthy men. The SEMGs of gross muscle activity simultaneously recorded with 4 electrode pairs from the agonist and antagonist sides in 3 displacement conditions with respect to parallel position, interelectrode distance, and rotation were compared. The amount of EMG integration (equivalent to the average SEMG amplitude) of each electrode pair was compared to the reference electrode pair with interelectrode distance of 40 mm placed on the center of the tested muscles. The average EMG difference ratios ranged 1.1-2.2%/mm in parallel shift, 1.0-1.9%/mm in distance shift, and 0.3-0.6%/degree in rotation shift. Displacement error of electrodes in separate recording instances should be reduced using anatomical landmarks, when SEMG is applied as a quantitative method to evaluate change in the states of involuntary movements.     

Effect of abdominal drawing-in maneuver during hip extension on the muscle onset time of gluteus maximus,hamstring, and lumbar erector spinae in subjects with hyperlordotic lumbar angle

Background

The abdominal drawing-in maneuver (ADIM) is used to prevent abnormal movements of the lumbar spine and pelvis during therapeutic exercises. This study compared the effects of ADIM on the muscle onset time of the hamstring, gluteus maximus, and erector spinae muscles during prone hip extension exercise in subjects with or without hyperlordotic lumbar angle. Forty healthy adults (18 male, 22 female) were recruited for this study.

Methods

The lumbar lordotic angles and pelvic tilt angles of the subjects were measured using the Avaliação postural analysis software. The subjects were divided into two groups: the lumbar hyperlordotic angle (LHLA) and lumbar normal lordotic angle (LNLA) groups. The muscle contraction onset time of the hamstring, gluteus maximus, and erector spinae were assessed using surface electromyography.

Results

During ADIM application, the muscle contraction onset time of the gluteus maximus was significantly increased in the LHLA group compared with the LNLA group.

Conclusions

ADIM application during prone hip extension was more effective for gluteus maximus onset time in the LHLA group. Therefore, ADIM during prone hip extension may be useful for gluteus maximus training in individuals with lumbar hyperlordosis.