Background: Considering the kinetic chain of the lower extremity, a pronated foot position (PFP) can affect malalignment of the lower extremity, such as a dynamic knee valgus (DKV). Although the DKV during several single-leg movement tests has been investigated, no studies have compared the differences in DKV during a single-leg step down (SLSD) between subjects with and without PFP. Objects: The purpose of this study was to compare the DKV during SLSD between subjects with and without PFP. Methods: Twelve subjects with PFP (9 men, 3 women) and 15 subjects without PFP (12 men, 3 women) participated in this study. To calculate the DKV, frontal plane projection angle (FPPA), knee-in distance (KID), and hip-out distance (HOD) during SLSD were analyzed by twodimensional video analysis software (Kinovea). Results: The FPPA was significantly lower in PFP group, compared with control group (166.4° ± 7.5° and 174.5° ± 5.5°, p < 0.05). Also, the KID was significantly greater in PFP group, compared with control group (12.7 ± 3.9 cm and 7.3 ± 2.4 cm, p < 0.05). However, the HOD not significantly differed between two groups (12.7 ± 1.7 cm and 11.4 ± 2.5 cm, p > 0.05). Conclusion: The PFP is associated with lower FPPA and greater KID. When assess the DKV during SLSD, the PFP should be considered as a crucial factor for occurrence of DKV.

Background: Prone hip extension (PHE) can be performed to measure the lumbopelvic motor patterns and motions. Imbalances in lumbopelvic muscle activity and muscle weakness can result in instability including pain in lumbopelvic region. The posterior oblique sling (POS) muscles contribute to dynamic lumbopelvic stability. In addition, POS are anatomically aligned with the trapezius muscle group according to shoulder positions. Objects: This study compared the electromyography (EMG) activity of POS and pelvic compensations during PHE with and without pre-activation of lower trapezius muscle (lowT). Methods: Sixteen healthy males were recruited. PHE was performed in randomized order: PHE with and without lowT pre-activation. Surface EMG signals were recorded for biceps femoris (BF), gluteus maximus (GM) (ipsilateral), lumbar multifidus (MF) (bilateral), and the lowT (contralateral). An electromagnetic tracking motion analysis was used to measure the angle of pelvic rotation and anterior tilting. Results: The ipsilateral GM and bilateral MF EMG amplitudes were greater during PHE with lowT pre-activation compared to PHE without lowT pre-activation (p<.05). The BF amplitude during PHE without lowT pre-activation was significantly greater than that during PHE with lowT pre-activation (p<.05). The angles of pelvic rotation and anterior tilting during PHE with lowT pre-activation were significantly smaller compared to PHE without lowT pre-activation (p<.05). Conclusion: PHE with lowT pre-activation, which is aligned with the POS, showed more increased MF and GM muscular activity with smaller lumbopelvic compensations in rotation and anterior tilting compared to PHE without lowT pre-activation.

The study aimed to compare the effect of the treadmill walking training combined with obstacle-crossing (TWT-OC) and treadmill walking training (TWT) on the walking function of patients with chronic stroke. 29 subjects volunteered to participate in this study; they were randomly assigned to either TWT-OC group (15 subjects) or TWT group (14 subjects). Subjects from the TWT-OC group underwent a treadmill walking combined with obstacles-crossing for 30 minutes daily, three days a week for four weeks, whereas subjects from the TWT group received only a treadmill walking. The 10 m walk test (10MWT), 6-min walk test (6MWT), berg balance scale (BBS), timed up and go test (TUG), activities-specific balance confidence-Korean version (ABC-K), and walking ability questionnaire (WAQ) were measured before and after the 4-week training. The TWT-OC group showed significantly better functional mobility of walking and balance measured by 6MWT (p<.01), BBS (p<.01), and TUG scores (p<.05) when compared with those of the TWT group. Further, within-group comparison showed significant improvement in all variables (p<.01) except for 10MWT. These findings suggest that the TWT-OC and TWT may be helpful for improving the walking function of patients with chronic stroke, and the TWT-OC has probably more favorable outcomes for chronic stroke, however, further trials with wider range of subjects are warranted for generalization and clinical relevance.

The aim of this study was to investigate the effectiveness of self-stretching exercises for iliotibial band (ITB) (Side-lying; right hip and knee were flexed to support the pelvis while left hip was extended and adducted, Standing A; side-bending of the trunk on standing with crossed leg, Standing B; same as Standing A, except the hands were clasped overhead and shifted right side, and Standing C; same as Standing B, except moving the arms diagonally downward) to help determine the most effective self-stretching method to stretch ITB. Twenty-one healthy subjects who do not have ITB shortness from Yonsei University (14 men and 7 women) between the ages of 18 to 28 years voluntarily participated. Ultrasound was performed to measure the thickness of the ITB between the long axis of the ITB and the level parallel to the lateral femoral epicondyle during four self-stretching exercises. All data were found to approximate a normal distribution. We used a one-way repeated-measures analysis of variance (ANOVA) to compare the thickness of the ITB among all self-stretching exercises. The level of significance was set at =.05. The ANOVA was followed by Bonferroni's correction. The overall mean of ITB thickness was mm ( standard deviation) in resting status. The change in the ITB thickness in percentages between the tested position of each self-stretching exercises and resting status was significant (p<.05) (Side-lying with 95% confidence interval [CI]=21.99~31.25%; Standing A with 95% CI=22.09~36.84%; Standing B with 95% CI=37.31~50.81%; Standing C with 95% CI=48.25~59.29%). Results indicated significant differences among four self-stretching exercises except Side-lying versus Standing A (p<.01). Based on these findings, the Standing C self-stretching exercise was the most effective in stretching the ITB thickness among four types of ITB self-stretching exercises. Additionally, the Side-lying self-stretching exercise using gravity to stretch the ITB is recommended as a low-load (low-intensity), long-duration stretch.

The purpose of this study was to compare the muscle activity of the abdominal and lumbar multifidus during unilateral prone hip extension on the floor and on a round foam roll. Fifteen healthy participants were recruited. They were instructed to perform a unilateral hip extension on the floor and on a round foam roll in the prone position. Surface electromyography (EMG) signals were recorded from bilateral lumbar multifidus (LM), external oblique (EO), and internal oblique (IO) muscles. A paired t-test was used to compare muscle activity, with the level of significance set at =.05. The results showed that bilateral LM, EO, IO EMG activity during right-hip extension on a round foam roll was greater than that on the floor, and EMG activity of bilateral LM, right EO, and left IO during left-hip extension on a round foam roll was greater than that on the floor (p<.05). These findings suggest that the unilateral hip-extension exercise on a round foam roll can be used to activate the lumbar multifidus and abdominal oblique muscles and causes a different increasing pattern between the two lifting sides.

The purpose of this study was to assess the agreement of manual muscle testing (MMT) and test-retest reliability of a hand held dynamometer for the posterior gluteus medius muscle, with and without lumbar stabilization, using a pressure biofeedback unit for patients with low back pain. The pressure biofeedback unit was used to minimize the substitute motion of the lumbopelvic region during hip abduction in patients lying on their side. Fifteen patients with low back pain participated in this study. A tester determined the MMT grades of the posterior gluteus medius with and without the pressure biofeedback unit. Active hip abduction range of motion with an inclinometer and the strength of their posterior gluteus medius using a hand held dynamometer were measured with and without the pressure biofeedback unit in the MMT position. The agreement of the grade of muscle strength in the MMT, and intra-rater reliability of both the active hip abduction range of motion and the strength of posterior gluteus medius were analyzed using the weighted kappa and intraclass correlation coefficient (ICC), respectively. The agreement of MMT with the pressure biofeedback unit (weighted kappa=.92) was higher than the MMT (weighted kappa=.34)(p<.05). The inclinometer with pressure biofeedback unit measurement of the active hip abduction range of motion had an excellent intra-rater reliability (ICC=.90). Also, the hand held dynamometer with pressure biofeedback unit measure of strength of the posterior gluteus medius had a good intra-rater reliability (ICC=.85). Therefore, the test for muscle strength with pressure biofeedback unit will be a reliable method for the determination of the MMT grades or amount of posterior gluteus medius muscle strength and the measurement of the range of motion for hip abduction in patients with low back pain.

Although there have been various studies related to the body's movement from a sitting to a standing position (sit-to-stand task), there is limited information on the kinematic changes on the frontal and transverse planes. The purpose of this study was to ascertain how pelvic tilt affects kinematic changes in the frontal and transverse planes in the hip and knee joints during a sit-to-stand task. For this study, 33 healthy participants (13 female) were recruited. Each participant rose from a sitting to a standing posture at his or her preferred speed for each of three different pelvic tilt trials (anterior, posterior, and neutral), and the measured angles were analyzed using a 3-D motion analysis system. A one-way repeated measure analysis of variance was performed with Bonferroni's post hoc test. In addition, an independent t-test was carried out to determine the sex differences in hip and knee joint kinematic changes during the sit-to-stand tasks. The results were as follows: 1) The hip and knee joint angle in the frontal and transverse planes showed a significant difference between the different pelvic tilt postures during sitting in the pre-buttock lift-off phase (pre-LO) (p<.05). Compared to the posterior pelvic tilt posture, the anterior pelvic tilt posture involved significantly greater hip joint adduction and internal rotation, knee joint adduction, and reduced internal rotation of the knee joint. 2) Sex differences were found with significant differences for males in the initial and maximal angles in the frontal plane of the hip and knee joint (p<.05). Females had a significantly smaller initial abduction angle of the hip joint and a significantly greater maximal angle of the hip adduction joint. These results suggest that selecting a sit-to-stand exercise for pelvic tilt posture should be considered to control abnormal movement in the lower extremities.

The purpose of this study was to measure intra-rater and inter-rater reliability and range of motion for measurement of passive shoulder internal rotation range of motion and to compare anterior glide distance of humeral head in three methods. Fifty healthy subjects and fifty patients with shoulder musculoskeletal pain were recruited for this study. The subjects' passive shoulder internal rotation range of motion was measured by visual estimation, manual stabilization, and pressure biofeedback unit methods. In two trials, measurements were performed on each subject by two examiners. Intraclass correlation coefficient (ICC(3,1)) was used to determine the reliability of each measurement. The intra-rater reliability of the three methods was excellent (ICC=.77~.93) in both groups. The inter-rater reliability of the visual estimation method was poor (ICC=.20, .29), the manual scapular stabilization method was poor and fair (ICC=.09, .50), and the pressure biofeedback unit method was excellent (ICC .86, .75) in the experimental and control groups. In the experimental group, the difference of examined range of motion by each examiner was significant in the visual estimation method and manual scapular stabilization method, but there was an insignificant difference between the groups is the pressure biofeedback unit method. This result suggests that the intra-rater and inter-rater reliability of a pressure biofeedback unit was better than the other methods. The difference in distance of the anterior glide of humeral head was insignificant among all the methods. The pressure biofeedback unit method was the most reliable method, so it is proposed to be a new and reliable method to measure internal rotation range of motion.