The ratio of medial and lateral hamstring muscle thickness does not correlate with the lateral tibial rotation angle in the standing position in healthy young adults.

[Purpose] To investigate the relationship between the lateral tibial rotation angle during knee joint flexion and the medial and lateral hamstring muscle thickness ratio during knee joint extension while resting, doing nothing, in upright standing position. The lateral tibial torsion is an important factor of orthopedic knee joint diseases as well as other weight bearing joint diseases such as osteoarthritis, meniscus syndrome, anterior cruciate ligament rupture, etc. [Subjects and Methods] Thirty healthy young adults participated in this study. The thickness of the medial and lateral hamstrings was measured using ultrasonographic imaging technique during knee extension in a resting position. The angle of tibial rotation was measured with 2D motion analysis during knee flexion in a half kneeling position. Pearson's correlation coefficient was used to test the relationship. [Results] There is no significant relationship between the angle of lateral tibial rotation and the ratio of hamstring muscle thickness. [Conclusion] These results demonstrate that lateral tibial rotation is not affected by hamstrings during rest in a standing position.

Comparison of muscle activity of wrist extensors and kinematics of wrist joint during wrist extension in automobile assembly line workers with and without lateral epicondylitis.

BACKGROUND: Overuse of the extensor carpi radialis (ECR) may play a role in the development of lateral epicondylitis (LE). However, no studies have investigated the muscle activity ratio between the ECR and extensor carpi ulnaris (ECU) associated with the kinematics during wrist extension in workers with LE. OBJECTIVE: We compared the ratio (ECR/ECU) of muscle activity between the ECR and ECU and the kinematics of the wrist during wrist extension between workers with and without LE. METHODS: Fifteen automobile assembly line workers with LE and 15 workers without LE participated in this study. The ratio of muscle activity was measured using surface electromyography, and wrist kinematics were measured by a three-dimensional motion analysis system while the workers extended their wrists actively to the maximum range to which they did not feel uncomfortable. RESULTS: Significantly greater ratios of muscle activity, ranges of radial deviation, and combined motion of radial deviation and extension (CMDE) were shown in workers with LE compared to those without LE. Also, the range of wrist extension was significantly lower in workers with LE than in those without LE. CONCLUSIONS: Quantifying the ratio of muscle activity with altered kinematics of wrist extension may help researchers to understand why overuse of ECR is occurring and explain LE development in automobile assembly line workers.

Effects of tibial rotation on Ober's test and patellar tracking.

BACKGROUND: The purpose of this study was to investigate the effects of tibial position on ITB flexibility and patellar position. METHODS: A total of 31 asymptomatic subjects (21 males, 10 females) were recruited for this investigation. Adduction angle was measured by Ober's test, and PCD was measured by ultrasonography in three different tibial rotation conditions: N, IR, and ER. RESULTS: Repeated measures ANOVA revealed a significant difference in adduction angle and PCD among three different tibial positions (P<0.05). Adduction angle was significantly greater in the N tibial position than in ER (P<0.05). The PCD was significantly greater in N position than in IR (P<0.05). However, the PCD was significantly smaller in IR compared with the N position (P<0.05). CONCLUSIONS: These findings support that tibial rotation influences the flexibility of ITB and patellar positions. Therefore, excessive tibial rotation can cause inappropriate patellar positions that eventually lead to knee injury. Therapists should consider tibial rotation when measuring adduction angles because tibial rotation can change Ober's test results and contribute to the consistency of ITB length measurements. LEVEL OF EVIDENCE: Level IV.

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

PURPOSE: To investigate how the erector spinae (ES) and gluteus maximus (GM) muscle activity and the anterior pelvic tilt angle change with different hip abduction angles during a bridging exercise. METHODS: Twenty healthy participants (10 males and 10 females, aged 21.6 ± 1.6) voluntarily participated in this study. Surface electromyography (EMG) signals were recorded from the ES and GM during bridging at three hip abduction angles: 0°, 15°, and 30°. Simultaneously, the anterior pelvic tilt angle was measured using Image J software. RESULTS: The EMG amplitude of the GM muscle and the GM/ES EMG ratio were greatest at 30° hip abduction, followed by 15° and then 0° hip abduction during the bridging exercise. In contrast, the ES EMG amplitude at 30° hip abduction was significantly lesser than that at 0° and 15° abduction. Additionally, the anterior pelvic tilt angle was significantly lower at 30° hip abduction than at 0° or 15°. CONCLUSIONS: Bridging with 30° hip abduction can be recommended as an effective method to selectively facilitate GM muscle activity, minimize compensatory ES muscle activity, and decrease the anterior pelvic tilt angle.

Comparison of psoas major muscle thickness measured by sonography during active straight leg raising in subjects with and without uncontrolled lumbopelvic rotation.

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 < 0.01). No significant change in thickness of the 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.

The relationship between length of the iliotibial band and patellar position in Asians.

BACKGROUND: Tightness of the iliotibial band (ITB) has been documented as a major factor in lateral patellar translation because the ITB inserts into the lateral border of the patella through the iliopatellar band. The aim of this study was to compare the patella-condyle distance (PCD) between subjects with and without ITB tightness. We also investigated the relationship between ITB length and lateral patellar translation in hip adduction. METHODS: In 40 healthy volunteers, we measured the ITB length with Ober's test and the PCD at two hip positions (neutral and 20° adduction) using ultrasonography. Lateral patellar translation in hip adduction was calculated by subtracting the PCD at the adduction position from the hip neutral position. RESULTS: Twenty-three of the 40 subjects had ITB tightness; these subjects had a significantly laterally positioned patella at 20° adduction of the hip (p=0.044). Patients with ITB tightness also had greater lateral patellar translation in hip adduction than patients without tightness (p=0.000). The ITB length was moderately correlated with the PCD at 20° adduction of the hip (r=0.427, p=0.042) and strongly negatively correlated with lateral patellar translation (r=-0.717, p<0.000). CONCLUSIONS: These findings support the hypothesis that increasing ITB tension has a significant effect on the position of the patella and therefore affects translation of the patella. However, these findings do not indicate that ITB length is the only cause of lateral patellar translation; further studies are needed to assess the relative importance of different factors that could affect patellar position.

Comparison of the effects of local cryotherapy and passive cross-body stretch on extensibility in subjects with posterior shoulder tightness.

The objective was to compare the immediate effects of local cryotherapy (LC) and passive cross-body stretch on the extensibility of the posterior shoulder muscle in individuals with posterior shoulder tightness. Eighty-seven healthy subjects with a between-shoulder difference in internal rotation (IR) range of motion (ROM) greater than 10° were randomly divided into three groups: LC group, stretching group, and control group (n = 29 in each group). Subjects in the LC group received LC on infraspinatus and posterior deltoid muscles and subjects in the stretching group performed passive cross-body stretch. Stretch sensation was measured at the end range of passive IR and horizontal adduction (HA) using numerical rating scale, and the pressure pain threshold (PPT) at the infraspinatus and posterior deltoid muscles was measured using pressure algometry. Passive and active ROM of IR and HA of the glenohumeral joint were measured using an inclinometer. All measurements were performed at pre-intervention, post- intervention, and 10-min follow-up. Stretch sensation was significantly decreased and PPT was significantly increased in the LC and stretching groups at post-intervention, and these effects were maintained at 10-min follow-up, compared to the control group. Both the LC group and stretching group had a significantly greater increase in passive and active ROM of IR and HA, compared to the control group at post-intervention and 10-min follow-up. However, there were no significant differences in stretch sensation, PPT, or ROM of IR and HA between the LC group and stretching group. LC can be used to decrease the stretch sensation and increase PPT and ROM of IR and HA as much as a stretching exercise. LC could be an alternative method for increasing the restricted ROM of glenohumeral IR and HA for individuals with posterior shoulder tightness, especially for patients and sports players who have severe stretching discomfort. Key PointsLocal cryotherapy (LC) decreased the uncomfortable stretch sensation, and increased the pressure pain threshold (PPT) of infraspinatus and posterior deltoid muscles in subjects with posterior shoulder tightness.Decreased stretch sensation by LC without passive stretching could improve the passive and active ROM of internal rotation and horizontal adduction in subjects with posterior shoulder tightness, similar to cross-body stretch.LC can be an alternative method to increase extensibility when individuals with posterior shoulder tightness have high stretch sensitivity and low PPT in the infraspinatus and posterior deltoid muscles.

Immediate effect of walking with talus-stabilizing taping on ankle kinematics in subjects with limited ankle dorsiflexion.

OBJECTIVE: To determine the effects of walking with talus-stabilizing taping (TST) on ankle dorsiflexion (DF) and heel-off time in the stance phase of gait and ankle DF passive range of motion (PROM). DESIGN: Pre- and post-intervention study. SETTING: University motion analysis laboratory. PARTICIPANTS: Ten subjects participated in this study. Sixteen ankles with limited ankle DF PROM were tested. MAIN OUTCOME MEASURES: Ankle DF PROM was measured using a goniometer, and maximum ankle DF before heel-off and time to heel-off in the stance phase of gait were measured using a 3D motion analysis system before and after walking with TST. Data were analyzed using a paired t-test. RESULTS: Ankle maximum DF before heel-off (p = 0.001), time to heel-off during the stance phase of gait (p = 0.005), and ankle DF PROM (p < 0.001) were significantly increased post-intervention compared with pre-intervention. CONCLUSIONS: Walking with TST is an effective self-exercise for improving ankle kinematics during gait and increasing ankle DF PROM in individuals with limited ankle DF PROM.

The importance of a normal breathing pattern for an effective abdominal-hollowing maneuver in healthy people: an experimental study.

CONTEXT: A normal breathing pattern while performing the abdominal-hollowing (AH) maneuver or spinal-stabilization exercise is essential for the success of rehabilitation programs and exercises. In previous studies, subjects were given standardized instructions to control the influence of respiration during the AH maneuver. However, the effect of breathing pattern on abdominal-muscle thickness during the AH maneuver has not been investigated. OBJECTIVE: To compare abdominal-muscle thickness in subjects performing the AH maneuver under normal and abnormal breathing-pattern conditions and to investigate the effect of breathing pattern on the preferential contraction ratio (PCR) of the transverse abdominis. DESIGN: Comparative, repeated-measures experimental study. SETTING: University research laboratory. PARTICIPANTS: 16 healthy subjects (8 male, 8 female) from a university population. MEASUREMENT: A real-time ultrasound scanner was used to measure abdominal-muscle thickness during normal and abnormal breathing patterns. A paired t test was used to assess the effect of breathing pattern on abdominal-muscle thickness and PCR. RESULTS: Muscle thickness in the transverse abdominis and internal oblique muscles was significantly greater under the normal breathing pattern than under the abnormal pattern (P < .05). The PCR of the transverse abdominis was significantly higher under the normal breathing pattern compared with the abnormal pattern (P < .05). CONCLUSION: The results indicate that a normal breathing pattern is essential for performance of an effective AH maneuver. Thus, clinicians should ensure that patients adopt a normal breathing pattern before performing the AH maneuver and monitor transverse abdominis activation during the maneuver.

Serratus anterior muscle activation during knee push-up plus exercise performed on static stable, static unstable, and oscillating unstable surfaces in healthy subjects.

OBJECTIVES: To compare electromyographic (EMG) activity of the serratus anterior (SA) during knee push-up plus exercises according to various surfaces (static stable, static unstable, and oscillating unstable surfaces). STUDY DESIGN: Comparative study by repeated measures. SETTING: Yonsei University laboratory. PARTICIPANTS: In total, 15 healthy male subjects participated. MAIN OUTCOME MEASURES: The subjects performed knee push-up plus exercises on three different surfaces: static stable, static unstable, and oscillating unstable surfaces. Surface EMG activity of the SA for the peak and average amplitudes were collected from the dominant arm and presented as a percentage of the maximal voluntary contraction. A one-way repeated-measures ANOVA with a Bonferroni post hoc test was performed to compare differences in SA EMG activity according to the surface. RESULTS: The peak and average amplitudes of SA activity were significantly greater during knee push-up plus on the oscillating unstable surface than on the static stable or static unstable surfaces (p < 0.01). Additionally, there was no significant difference between the stable and static unstable surfaces (p > 0.05). CONCLUSIONS: Knee push-up plus exercise on an oscillating unstable surface activates the SA more than the same exercise on static stable and static unstable surfaces.

Short-term effects of self-mobilization with a strap on pain and range of motion of the wrist joint in patients with dorsal wrist pain when weight bearing through the hand: a case series.

Dorsal wrist pain frequently occurs in weight bearing through the hand in patients with distal radius stress injuries, scaphoid impaction syndrome, and dorsal impingement. To improve the wrist extension motion, joint mobilization has been used. However, there is no report on the effects of mobilization on the range of motion (ROM) and pain onset in patients with dorsal wrist pain when weight bearing through the hand. This study determined the effects of self-mobilization with a strap (SMWS) while weight bearing through the hand on the ROM and force generated at the onset of pain (FGOP) and intensity in the wrist joints of patients with dorsal wrist pain. Fifteen patients (six men, nine women) with dorsal wrist pain during weight bearing through the hand were recruited from a workplace-based work-conditioning center. SMWS was applied during five visits for a 1-week period. Both passive and active wrist extension ROM, FGOP, and pain intensity (PI) while pushing down through the hand were measured before and after SMWS. Passive and active ROM of wrist extension and FGOP increased significantly after the five sessions over 1 week of SMWS (p < 0.05). PI decreased significantly after the five sessions of SMWS (p < 0.05). These results suggest that SMWS can be used to increase wrist extension ROM and decrease wrist pain in patients with dorsal wrist pain during weight bearing through the hand.

Musculoskeletal predictors of movement quality for the forward step-down test in asymptomatic women.

STUDY DESIGN: Cross-sectional. OBJECTIVE: To investigate the interrater reliability of movement-quality ratings for the forward step-down (FSD) test and to compare hip muscle strength and lower extremity joint range of motion and muscle flexibility among asymptomatic women with different levels of movement quality. BACKGROUND: The interrater reliability of the FSD test has not yet been investigated. Additionally, it is not known whether differences in musculoskeletal measures exist among individuals with different levels of movement quality during the FSD test. METHODS: Two physical therapists assessed movement quality during the FSD test in 26 asymptomatic women (mean ± SD age, 22.7 ± 0.9 years). Hip muscle strength and lower extremity joint range of motion and muscle flexibility were also assessed. The interrater reliability of the FSD test was estimated by using the kappa coefficient and percent agreement. Differences in musculoskeletal measures based on movement quality were assessed by independent t tests. RESULTS: The kappa coefficient and percent agreement for rating the quality of movement on the FSD test were 0.80 (95% confidence interval: 0.57, 1.00) and 85%, respectively. The subjects with moderate movement quality had significantly less strength of the hip abductors, less knee flexion range of motion measured in prone (quadriceps flexibility), and less hip adduction range of motion measured in sidelying (iliotibial band/tensor fascia latae flexibility) compared to those with good movement quality. CONCLUSION: There was good agreement for the rating of movement quality during the FSD test, and there were physical attributes that distinguished those with moderate from those with good quality of movement.