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Context: Electrical muscle stimulation (EMS) was designed for artificial muscle activation or superimposed training. Objectives: To compare the effects of 8 weeks of superimposed technique (ST; application of electrical stimulation during a voluntary muscle action) and EMS on the cross-sectional area of the rectus abdominis, lateral abdominal wall, and on lumbopelvic control. Setting: University research laboratory. Design: Randomized controlled trial. Participants: Fifty healthy subjects were recruited and randomly assigned to either the ST or EMS group. Intervention: The participants engaged with the electrical stimulation techniques (ST or EMS) for 8 weeks. Main Outcome Measures: In all participants, the cross-sectional area of the rectus abdominis and lateral abdominal wall was measured by magnetic resonance imaging and lumbopelvic control, quantified using the single-leg and double-leg lowering tests. Results: There were no significant differences in the cross-sectional area of the rectus abdominis (right: P = .70, left: P = .99) or lateral abdominal wall (right: P = .07, left: P = .69) between groups. There was a significant difference between groups in the double-leg lowering test (P = .03), but not in the single-leg lowering test (P = .88). There were significant differences between the preintervention and postintervention in the single-leg (P P Conclusions: ST could improve lumbopelvic control in the context of athletic training and fitness.

Because patients with nonspecific chronic low back pain (NSCLBP) are heterogeneous, subgrouping patients with NSCLBP might clarify the research findings. NSCLBP in the direction of extension movement, namely active extension pattern (AEP), is common during prolonged standing.Predictors of pain intensity and dysfunction were determined in prolonged standing service workers (PSSWs) with NSCLBP subclassified as AEP in the motor impairment subgroup.Variables were measured using questionnaires including a visual analog scale (VAS), the Oswestry Disability Index (ODI), Borg Rating of Perceived Exertion (RPE) Scale, and Korean Occupational Stress Scale (KOSS). Postural assessment was performed by measuring pelvic anterior tilting angle (PATA). The smart KEMA measurement system was used to evaluate hip flexion, hip extension (HE), and knee flexion range of motion (ROM), as well as hip extensor strength, hip abductor strength (HArS), hip external rotator strength (HERrS), hip internal rotator strength, knee extensor strength, and knee flexor strength, and lumbopelvic stability (LS) in 78 PSSWs with NSCLBP subclassified as AEP.In prediction models, HArS, LS, PATA, KOSS and HE ROM accounted for 40.1% of the variance in the VAS (p 0.05); predictors of dysfunction included the HERrS and age, which accounted for 11.9% of the variance in the ODI (p 0.05) in multiple regression models when using a stepwise selection procedure.The present results indicate that HArS and HERrS, LS, PATA, KOSS, HE ROM and age should be considered for evaluating and predicting NSCLBP subclassified as AEP in PSSWs, and when designing interventions.

It is unclear which factors contribute to the developing pressure pain hypersensitivity of the upper trapezius, a type of neurophysiological hyperexcitability. The present study investigated the relationship between physical and psychological factors and pressure pain hypersensitivity of the upper trapezius for each sex. In total, 154 individuals with neck/shoulder myofascial pain participated, among 372 food service workers. Participants completed a questionnaire (Beck Depression Inventory, and Borg Rating of Perceived Exertion scale) and were photographed to measure posture. Pressure pain sensitivity, 2 range of motions (cervical lateral bending and rotation), and 4 muscle strengths (serratus anterior, lower trapezius [LT], biceps, and glenohumeral external rotator) were measured by a pressure algometer, iPhone application, and handheld dynamometer, respectively. For each sex, forward multivariate logistic regression was used to test our a priori hypothesis among selected variables that a combination of psychosocial and physical factors contributed to the risk for pressure pain hypersensitivity. In multivariate analyses, LT strength (odds ratio = 0.94, 95% confidence interval = 0.91-0.97, P = .001) was the only significant influencing factor for pressure pain hypersensitivity in men. Dominant painful ipsilateral cervical rotation range of motion (odds ratio = 0.96, 95% confidence interval = 0.92-0.99, P = .037) was the only influencing factor for pressure pain hypersensitivity in women. LT strength and dominant painful ipsilateral cervical rotation range of motion could serve as guidelines for preventing and managing pressure pain hypersensitivity of the upper trapezius in food service workers with nonspecific neck/shoulder myofascial pain.

BACKGROUND Increased genu recurvatum (GR) angle is a risk factor for knee injury. Identification of factors causing GR is important for the prevention and rehabilitation of GR. Few studies have investigated the association between muscle strength and GR. OBJECTIVE To examine the association between GR angle and hip and knee muscle strength in standing workersMETHODS:The participants in this study were 110 healthy volunteers (59 male, 51 female) who performed standing work in a theme park. The GR angle, muscle strength, and strength ratio of the lower extremities were measured to determine their associations with GR. The GR angle was measured using a Smart KEMA motion sensor, and muscle strength was assessed using a Smart KEMA strength sensor. Stepwise multiple regression models were used to investigate which muscles contributed most to the extent of the GR angle. RESULTS Stepwise multiple regression analysis showed that the decreased hip external rotator to hip internal rotator ratio, increased knee extensor to knee flexor ratio, and young age were associated with an increased GR angle. CONCLUSIONS Many factors are known to increase the GR angle. However, this study investigated the roles of only hip and knee muscle strength. The results suggest that muscle strength ratios are more important than the weakness of any muscle.

BACKGROUND Neuromuscular electrical stimulation (NMES) devices for abdominal muscles are being marketed to the general public to improve physical appearance. Abdominal muscles play an important role in lumbopelvic stability for optimizing performance. We investigated the effects of NMES training of abdominal muscles on muscle size, muscle strength, endurance, and lumbopelvic stability. METHODS Twenty-three subjects (12 females, 11 males) performed abdominal muscle NMES training for 8 weeks. Before and after NMES training, we measured muscle size (cross-sectional area [CSA] of the rectus abdominals [RA] and lateral abdominal wall [LAW]) by magnetic resonance imaging, muscle strength (trunk flexor and side bridge strength), endurance (trunk flexor and side bridge endurance time), and lumbopelvic stability (one-leg loading test). RESULTS There were significant increases between pre- and post-NMES training differences in the size (CSA of RA 21.7-25.4%, P

Increased activity of the serratus anterior (SA) muscle combined with decreased activity of the pectoralis major (PM) muscle during scapular protraction exercise is a widely used method for selective strengthening of the former muscle. However, the role played by the PM during maximal scapular protraction remains unclear. The objective of our study was to investigate the effects of horizontal shoulder abduction (decreasing PM activity) and adduction (increasing activity) on the strength and activity of the scapular protractors (the SA and PM) during maximal protraction. Twenty-nine healthy males performed maximal scapular protraction combined with horizontal shoulder abduction or adduction. The strength and activity of the PM and SA decreased significantly (both p < 0.01) during maximal scapular protraction combined with horizontal shoulder abduction, compared with maximal scapular protraction alone, but increased significantly (both p < 0.01) when maximal scapular protraction was combined with horizontal shoulder adduction. We thus conclude that the PM stabilizes the activated SA during maximal scapular protraction, which effectively increases SA activity and scapular protraction strength in the serratus punch posture.

This study was conducted in order to compare the strength of scapular elevator and shoulder abductor with and without restricted scapular elevation between male subjects with and without myofascial trigger points in the upper trapezius.In total, 15 male subjects with myofascial trigger points, and 15age- and weight-matched male subjects without myofascial trigger points in the upper trapezius. Each subject was measured in the strength of maximum isometric scapular elevation and shoulder abduction with and without restricted scapular elevation. Maximum isometric contractions were measured using the Smart KEMA strength measurement system. Independent t-tests were used to compare shoulder strength values between the myofascial trigger points and non- myofascial trigger points groups.The results showed that shoulder abductor strength in the group with myofascial trigger points (5.64kgf) was significantly lower than in the group without myofascial trigger points (11.96kgf) when scapular elevation was restricted (p0.05). However, there was no significant difference in the strength of the scapular elevator or shoulder abductor between groups (p0.05).These findings suggest that decreased strength in the shoulder abductor with restricted scapular elevation should be considered in evaluating and treating individuals with myofascial trigger points of the upper trapezius.

The purposes of this study were to determine the intra-rater test-retest reliability of a smart phone-based measurement tool (SBMT) and a three-dimensional (3D) motion analysis system for measuring the transverse rotation angle of the pelvis during single-leg lifting (SLL) and the criterion validity of the transverse rotation angle of the pelvis measurement using SBMT compared with a 3D motion analysis system (3DMAS).Seventeen healthy volunteers performed SLL with their dominant leg without bending the knee until they reached a target placed 20 cm above the table. This study used a 3DMAS, considered the gold standard, to measure the transverse rotation angle of the pelvis to assess the criterion validity of the SBMT measurement. Intra-rater test-retest reliability was determined using the SBMT and 3DMAS using intra-class correlation coefficient (ICC) [3,1] values. The criterion validity of the SBMT was assessed with ICC [3,1] values.Both the 3DMAS (ICC = 0.77) and SBMT (ICC = 0.83) showed excellent intra-rater test-retest reliability in the measurement of the transverse rotation angle of the pelvis during SLL in a supine position. Moreover, the SBMT showed an excellent correlation with the 3DMAS (ICC = 0.99).Measurement of the transverse rotation angle of the pelvis using the SBMT showed excellent reliability and criterion validity compared with the 3DMAS.

Background: Weakness of evertor strength is controversial in chronic ankle instability (CAI). Ankle evertor muscles are attached to the toe joints as well as to the metatarsal bone. Therefore, it is necessary to consider toe joint position for the measurement of evertor strength. The purpose of this study was to compare ankle evertor strength and muscle activity during eversion with and without toe flexion (TF) in individuals with CAI and individuals in a healthy group. Methods: Fifteen subjects with CAI and 15 healthy subjects participated in this study. Isometric ankle evertor strength and muscle activity of the peroneus longus (PL), peroneus brevis (PB), and extensor digitorum longus (EDL) were measured during eversion with and without TF. Results: The results indicated a significant interaction effect in evertor strength ( P = .03) and no significant interaction effect on EMG of the PL ( P = .08), PB ( P = .12), and EDL ( P = .28). However, measurements of muscle activity of the PL and PB between eversion with and without TF revealed a significant difference in the CAI group ( P < .01) and no significant difference in the healthy group (PL: P = .07; PB: P = .13). Conclusion: The results indicated that subjects with CAI had increased EDL compensation and reduced selective activation of the PL and PB during eversion. Clinical Relevance: Our findings suggest that clinicians should consider the activation of EDL when training the evertor of patients with CAI.

Background Previous studies suggested that patients with symptomatic intervertebral disc degeneration (IDD) of lumbar spine have reduced cross-sectional area (CSA) and functions of core muscles. However, reduced CSA and functions of core muscles have been observed not only in patients with symptomatic IDD but also in patients with other subgroups of low back pain (LBP). Thus, it is uncertain whether reduced CSA and functions of core muscles lead to IDD and LBP, or pain leads to reduced CSA and functions of core muscles in patients with symptomatic IDD. Therefore, this study aimed to compare the CSA and functions of core muscles between asymptomatic participants with and without IDD in magnetic resonance imaging (MRI). Methods Twenty asymptomatic participants (12 men and 8 women) participated in this study. Ten participants had asymptomatic IDD at L4–5. The others were healthy controls (without IDD at all levels of lumbar spine). The CSA of core muscles was measured using MRI. Maximal isometric trunk flexor strength and side bridge strength were measured by a Smart KEMA strength sensor. Trunk flexor endurance test, side bridge endurance test and plank endurance test were used to measure core endurance. Double legs loading test was used to measure core stability. Mann-Whitney U test was used to compare the differences between two groups. Results There were no significant differences in core muscle functions between the two groups (p > 0.05). Moreover, there was no significant difference in CSA between the two groups (p > 0.05). Conclusions There was no significant difference in CSA and core muscle functions between asymptomatic participants with and without IDD. These findings indicate that a degenerative or bulging disc in asymptomatic individuals has little effect on CSA and functions of core muscles, especially in young age. Therefore, the general core endurance test or strength test could not differentiate asymptomatic people with and without IDD of lumbar spine. Trial registration number Clinical Research information Service. KCT0004061. Registered 13 June 2019. retrospectively registered.

Kim, J-H, Kwon, O-Y, Hwang, U-J, Jung, S-H, Ahn, S-H, and Kim, H-A. Comparison of shoulder external rotator strength and the asymmetry ratio between workers with and without shoulder impingement syndrome. J Strength Cond Res 35(12): 3364-3369, 2021-Shoulder impingement syndrome (SIS) is the most common shoulder problem causing shoulder pain. Several studies have indicated that shoulder external rotator muscles provide dynamic stability to the shoulder joint. However, the relationship of SIS to changes in shoulder external rotator muscle strength remains controversial. The purpose of the study was to compare the shoulder external rotator strength and asymmetry ratio between workers with SIS and the normal group in a side-lying position. Twelve male industrial workers with SIS and the normal group of 12 workers participated in this study. A pulling sensor measured shoulder external rotator muscle strength in a side-lying position with the shoulder at 0° and 90° of flexion. The asymmetry ratio was calculated by a specific formula using the shoulder external rotator muscle strength of the dominant side and the unaffected side. Two-way analysis of variance was used to determine between-group differences in shoulder external rotator muscle strength and the asymmetry ratio among the 2 positions. Subjects with SIS did not exhibit significant differences in shoulder external rotator muscle strength in the side-lying position with the shoulder at 0° and 90° of flexion relative to the normal group. However, subjects with SIS had a significantly increased asymmetry ratio of shoulder external rotation strength in the side-lying position with the shoulder at 90° of flexion compared with the normal group. In conclusion, workers with SIS had an asymmetry of shoulder external rotator strength in side-lying with the shoulder at 90° of flexion.

Study Design: Cross-sectional comparison.Introduction: Forearm supination range of motion is often limited by short or stiff pronators. Many studies have examined maximal isometric forearm supinati...

Context:The push-up-plus (PP) exercise has been recommended for strengthening of the serratus anterior (SA). Previous studies have investigated the effect of different stability properties of the base of support to adjust the difficulty level of SA muscle-strengthening exercises in the PP position. However, the optimal humeral-elevation angle (HEA) for selective activation and maximum contraction of the SA during PP has not been investigated.Objectives:To assess the effects of HEA during PP on electromyographic (EMG) activity in the SA, upper trapezius (UT), and pectoralis major (PM) and on the UT:SA and PM:SA activity ratios.Design:Comparative, repeated-measures design.Setting:University research laboratory.Participants:29 healthy men.Main Outcome Measures:The subjects performed PP at 3 different HEAs (60°, 90°, and 120°); EMG activity in the SA, UT, and PM was measured, and the UT:SA and PM:SA activity ratios were calculated. Differences in muscle activity and ratios between the 60°, 90°, and 120° HEAs were assessed using 1-way repeated-measures analysis of variance; the Bonferroni correction was applied.Results:SA muscle activity was significantly increased, in order of magnitude, at the 120°, 90°, and 60° HEAs. UT:SA and PM:SA activity ratios were significantly greater during performance of the PP at an HEA of 60° than at HEAs of 120° and 90°.Conclusion:The results suggest that an HEA of 120° should be used during performance of the PP because it produces greater SA activation than HEAs of 60° and 90°.

Objectives The aim of the present study was to examine the intra- and inter-rater reliabilities of the leg lateral reach test as a screening tool for thoraco-lumbo-pelvic rotation and to assess the relationship between leg lateral reach distance and thoraco-lumbo-pelvic rotation range in a supine position. Design Controlled laboratory study. Methods Thirty-six physically active participants were recruited. The leg lateral reach test was performed over 2 days. In the first session, two testers measured the distance of the leg lateral reach to determine the within-day inter-rater reliability, and one tester repeated the measurement on day 2 to determine the intra-rater reliability between days. The leg lateral reach test was performed three times per leg, and the mean value was used for data analysis. Reliability was determined using the intraclass correlation coefficient, standard error of measurement, and minimal detectable change. The correlation between leg lateral reach distance and thoraco-lumbo-pelvic rotation range was determined using Pearson correlation. Results Almost perfect intra- and inter-rater reliabilities were shown for the test [intraclass correlation coefficient 2,3 = 0.97 (95% confidence interval = 0.914–0.984) and 0.99 (0.974–0.996), respectively]. The within-day inter-rater standard error of measurement was 1.40 cm, and the minimal detectable change was 3.87 cm. The between-day intra-rater standard error of measurement was 2.66 cm, and the minimal detectable change was 7.37 cm. The Pearson correlation showed a moderate to good correlation between the leg lateral reach distance and the thoraco-lumbo-pelvic rotation range ( r = 0.73). Conclusions The leg lateral reach screening test is reliable for measuring thoraco-lumbo-pelvic rotation range and allows for practical measurement of the thoraco-lumbo-pelvic rotation range in a supine position.

To compare the surface electromyography (EMG) amplitude of the hip joint, including the gluteus maximus (GM), biceps femoris (BF), and semitendinosus (ST) muscles generated by three different exercises: prone hip extension (PHE), prone table hip extension (PTHE), and prone table hip extension with 90° knee flexion (PTHEK), with compensatory pelvic motions.Repeated-measure within-subject intervention.Sixteen-healthy males (mean age = 23.4 ± 2.2 years).EMG was used to collect EMG signals from the GM, erector spinae (ES), BF, and ST muscles. Furthermore an electromagnetic tracking motion analysis was also performed to measure the compensations.EMG amplitude differed significantly among the three conditions (PHE vs. PTHE vs. PTHEK) (p 0.05). The mean GM muscle activity increased significantly during the PTHEK (70.93% and 13.75% increases in %MVIC compared with the PHE and PTHE, respectively) (p 0.01). However, there was no significant difference in the kinematic data for rotation or anterior tilting angle of the pelvis among the three conditions (p 0.05).These results suggest that the PTHEK can be recommended as an effective method to strengthen the GM muscle without increased BF or ES muscle activities and without compensatory pelvic motions.

Findings about predictors of chronic lower-back pain (CLBP) were inconsistent and inconclusive in previous studies because patients with CLBP are heterogeneous. Subgrouping patients with CLBP, according to a CLBP classification system, might thus clarify the research findings. CLBP in the direction of lumbar flexion movement, that is, the flexion pattern, is common in clinical situations. Therefore, the purpose of this study was to determine the predictors of dysfunction (pain, disability) and health-related quality of life in the flexion pattern subgroup of patients with CLBP. A cross-sectional study of prospectively collected data. One hundred eight subjects in the flexion pattern subgroup of CLBP. Thirteen variables were measured: the visual analog scale (VAS), the Oswestry Disability Index (ODI), the Short Form-36 (SF-36), the Beck Depression Inventory (BDI), hip internal rotation range of motion, hip flexion range of motion, knee extension range of motion, knee extension with dorsiflexion range of motion, ratio forward flexion, knee extension strength, hip extension strength, hip flexion strength, and lumbopelvic stability. The models for predictors of lower-back pain in the CLBP flexion pattern subgroup included knee extension and the BDI as predictor variables that accounted for 8.1% of the variance in the VAS (P

Posterior shoulder tightness is related to shoulder conditions such as shoulder impingement and limited shoulder horizontal adduction (SHA). The purpose of this study was to compare the effects of self-cross body stretching (CBS) with and without scapular stabilization (SS) on SHA and shoulder internal rotation (SIR) range of motion (ROM) and shoulder horizontal adductor strength (SHAS) in subjects with limited SHA.Twenty-six subjects (14 males, 12 females) with limited SHA was participated in this study. The SS group and without stabilization (WS) group were assigned randomly. The SS group performed self-CBS with SS by applying belt just under the subject's axilla. The subjects were asked to perform self-CBS 4 times a week for 4 weeks. SHA and SIR RM were measured by Clinometer smartphone application, and SHAS by hand-held dynamometer before and after 4-week self-CBS.2 × 2 mixed analysis of variance (ANOVA) was used to identify the significance. If there was an interaction effect, t-test was used to confirm the simple effect. There was a significant interaction in SHA ROM and SHAS. The post-test value of SHA ROM was significantly greater in SS group than WS group (P0.0125). In SHAS, there was no significant difference between groups (P0.0125).SS during self-CBS could enhance to improve SHA, SIR ROM, and SHAS in individuals with limited SHA.

The aim of this study was to determine the inter-rater reliability of glenohumeral internal rotation (GIR) range of motion (ROM) and pressure measurements among four measurement methods: (1) Manual stabilization of the humeral head and coracoid process (MSHC) without applying consistent pressure (ACP) to both the stationary and the moving arms (BSaMA); (2) MSHC with ACP to the moving arm; (3) MSHC with ACP to the stationary arm; and (4) MSHC with ACP to BSaMA.Test-retest analyses.39 subjects with GIR deficit.GIR ROM and pressure were measured on the stationary or moving arm by four examiners using the Clinometer application and a pressure biofeedback unit.GIR ROM measurement with MSHC and ACP to the moving arm resulted in the lowest intra-class correlation coefficient (ICC = .43); the ICC for MSHC without ACP to BSaMA was .54; that for MSHC with ACP to the stationary arm was .77; and that for MSHC with ACP to BSaMA was highest, at .81.MSHC with ACP to both arms leads to reliable GIR ROM measurement in a clinical setting.

Shoulder pain occurs commonly in food service workers (FSWs) who repetitively perform motions of the upper limbs. Myofascial trigger points (MTrPs) on the upper trapezius (UT) are among the most common musculoskeletal shoulder pain syndromes. This study determined the psychological, posture, mobility, and strength factors associated with pain severity in FSWs with UT pain due to MTrPs. In this cross-sectional study, we measured 17 variables in 163 FSWs with UT pain due to MTrPs: a visual analog scale (VAS) pain score, age, sex, Borg rating of perceived exertion (BRPE) scale, beck depression inventory, forward head posture angle, rounded shoulder angle (RSA), shoulder slope angle, scapular downward rotation ratio, cervical lateral-bending side difference angle, cervical rotation side difference angle, glenohumeral internal rotation angle, shoulder horizontal adduction angle, serratus anterior (SA) strength, lower trapezius (LT) strength, bicep strength, and glenohumeral external rotator strength, in 163 FSWs with UT pain due to MTrPs. The model for factors influencing UT pain with MTrPs included SA strength, age, BRPE, LT strength, and RSA as predictor variables that accounted for 68.7% of the variance in VAS (P

Context:Prone hip extension has been recommended for strengthening the back and hip muscles. Previous studies have investigated prone hip extension conducted with subjects on the floor in the prone position. However, no study has compared 3 different table hip-extension (THE) positions in terms of the activities of the back- and hip-joint muscles with lumbopelvic motion.Objective:To identify more effective exercises for strengthening the gluteus maximus (GM) by comparing 3 different exercises (THE alone, THE with the abdominal drawing-in maneuver [THEA], and THEA with chair support under the knee [THEAC]) based on electromyographic muscle activity and pelvic compensation.Design:Repeated-measure within-subject intervention.Setting:University research laboratory.Participants:16 healthy men.Main Outcome Measures:Surface electromyography (EMG) was used to obtain data on the GM, erector spinae (ES), multifidus, biceps femoris (BF), and semitendinosus (ST). Pelvic compensation was monitored using an electromagnetic motion-tracking device. Exertion during each exercise was recorded. Any significant difference in electromyographic muscle activity and pelvic motion among the 3 conditions (THE vs THEA vs THEAC) was assessed using a 1-way repeated-measures analysis of variance (ANOVA) with Bonferroni post hoc test.Results:The muscle activities recorded by EMG differed significantly among the 3 exercises (P < .01). GM activity was increased significantly during THEAC (P < .01). There was a significant difference in lumbopelvic kinematics in terms of anterior tilting (F = 19.49, P < .01) and rotation (F= 27.38, P < .01) among the 3 exercises.Conclusions:The THEAC exercise was the most effective for strengthening the GM without overactivity of the ES, BF, and ST muscles and lumbopelvic compensation compared with THE and THEA.

Background The psoas major (PM) is important for stabilizing lumbopelvic region during active straight leg raising (ASLR). Uncontrolled lumbopelvic rotation (ULPR) frequently occurs during ASLR in subjects with poor lumbo-pelvic stability and may contribute to asymmetric symptoms including pain in lumbopelvic region. Objects This study compared the thickness of contralateral PM ( cPM ) using ultrasound imaging during ASLR in subjects with and without ULPR. Method Healthy male subjects (18 without ULPR, 19 with ULPR) were recruited. The thickness of the cPM during rest and ASLR without loading and with a 1-kg load was measured by ultrasound imaging. The relative muscle thickness was calculated as the thickness during ASLR/thickness at rest. Two-way mixed-model analysis of variance was used to identify significant differences in the relative thickness of the cPM between groups and within a loading status. The level of statistical significance was set at α = 0.05. Results The resting thickness of the cPM in subjects without ULPR did not differ from that of subjects with ULPR. The relative thickness of the cPM in subjects without ULPR was significantly greater during ASLR than that in subjects with ULPR both without loading and with a load ( p cPM was evident in those with ULPR. Conclusion The thickness of the cPM was significantly greater during ASLR in subjects without ULPR than with ULPR. This result indicates that persons with ULPR have less activation of the cPM to stabilize the lumbar spine during ASLR.