Jae-Seop Oh

Influence of forward head posture on scapular upward rotators during isometric shoulder flexion

SUMMARY We assessed the effects of forward head posture in the sitting position on the activity of the scapular upward rotators during loaded isometric shoulder flexion in the sagittal plane. Healthy volunteers (n = 21; 11 men, 10 women) with no history of pathology participated in the study. Subjects were instructed to perform isometric shoulder flexion with the right upper extremity in both the forward head posture (FHP) and neutral head posture (NHP) while sitting. Surface electromyography (EMG) was recorded from the upper trapezius, lower trapezius, and serratus anterior muscles. Dependent variables were examined by 2 (posture)×3 (muscle) repeated measures analysis of variance. Significantly increased EMG activity in the upper trapezius and lower trapezius and significantly decreased EMG activity in the serratus anterior were found during loaded isometric shoulder flexion with FHP. Thus, FHP may contribute to work-related neck and shoulder pain during loaded shoulder flexion while sitting. These results suggest that maintaining NHP is advantageous in reducing sustained upper and lower trapezius activity and enhancing serratus anterior activity as compared with FHP during loaded shoulder flexion.

Effect of medial arch support on displacement of the myotendinous junction of the gastrocnemius during standing wall stretching.

STUDY DESIGN Controlled laboratory study. OBJECTIVES To examine the effects of standing wall stretching with and without medial arch support (WMAS versus WOMAS) on the displacement of the myotendinous junction (DMTJ) of the medial gastrocnemius, rearfoot angle, and navicular height in subjects with neutral foot alignment and pes planus. BACKGROUND Standing wall stretching is often prescribed to increase ankle dorsiflexion range of motion for sports fitness and rehabilitation. However, the effect of standing wall stretching WMAS on DMTJ is unknown. METHODS Fifteen subjects with neutral foot alignment and 15 subjects with pes planus performed standing wall stretching under WMAS and WOMAS conditions. Measurements of DMTJ and rearfoot position were performed using ultrasonography and video imaging. Navicular height was measured using a ruler. Dependent variables were examined with a 2-way mixed-design analysis of variance. The 2 factors were foot type (neutral foot versus pes planus) and stretching condition (WMAS versus WOMAS). RESULTS There were significant interactions of medial arch support by foot type for DMTJ, rearfoot angle, and navicular drop (P<.001). A post hoc paired t test showed that standing wall stretching in the WMAS condition significantly increased the DMTJ, compared to stretching in the WOMAS condition, in subjects with neutral foot (mean +/- SD, 9.6 +/- 1.6 versus 10.5 +/- 1.6 mm; difference, 0.9 mm; 99% CI: 0.4-1.4 mm) and in those with pes planus (10.0 +/- 1.8 versus 12.7 +/- 2.0 mm; difference, 2.7 mm; 99% CI: 1.9-3.5 mm) (P<.001). When comparing WOMAS and WMAS, the difference in DMTJ (1.8 mm; 99% CI: 0.9-2.7 mm) was significantly greater in subjects with pes planus than in those with neutral foot (P<.001). CONCLUSION Standing wall stretching with medial arch support maintained subtalar joint neutral position and increased the length of the gastrocnemius in subjects with pes planus. When prescribing standing wall stretching, clinicians need to emphasize the use of medial arch support to effectively stretch the gastrocnemius in subjects with pes planus.

Comparison of Abdominal Muscle Activity During a Single-Legged Hold in the Hook-Lying Position on the Floor and on a Round Foam Roll

CONTEXT To improve trunk stability or trunk muscle strength, many athletic trainers and physiotherapists use various types of unstable equipment for training. The round foam roll is one of those unstable pieces of equipment and may be useful for improving trunk stability. OBJECTIVE To assess the effect of the supporting surface (floor versus round foam roll) on the activity of abdominal muscles during a single-legged hold exercise performed in the hook-lying position on the floor and on a round foam roll. DESIGN Crossover study. SETTING University research laboratory. PATIENTS OR OTHER PARTICIPANTS Nineteen healthy volunteers (11 men, 8 women) from a university population. INTERVENTION(S) The participants were instructed to perform a single-legged hold exercise while in the hook-lying position on the floor (stable surface) and on a round foam roll (unstable surface). MAIN OUTCOME MEASURE(S) Surface electromyography (EMG) signals were recorded from the bilateral rectus abdominis, internal oblique, and external oblique muscles. Dependent variables were examined with a paired t test. RESULTS The EMG activities in all abdominal muscles were greater during the single-legged hold exercise performed on the round foam roll than on the stable surface. CONCLUSIONS The single-legged hold exercise in the hooklying position on an unstable supporting surface induced greater abdominal muscle EMG amplitude than the same exercise performed on a stable supporting surface. These results suggest that performing the single-legged hold exercise while in the hook-lying position on a round foam roll is useful for activating the abdominal muscles.

Correlation of the Y-Balance Test with Lower-limb Strength of Adult Women.

[Purpose] The purpose of this study was to elucidate the relationship between Y-balance test (YBT) distance and the lower-limb strength of adult women. [Subjects] Forty women aged 45 to 80 years volunteered for this study. [Methods] The participants were tested for maximal muscle strength of the lower limbs (hip extensors, hip flexors, hip abductors, knee extensors, knee flexors, and ankle dorsiflexors) and YBT distances in the anterior, posteromedial, and posterolateral directions. Pearson’s correlation coefficient was used to quantify the linear relationships between YBT distances and lower-limb strength. [Results] Hip extensor and knee flexor strength were positively correlated with YBT anterior distance. Hip extensor, hip abductor, and knee flexor strength were positively correlated with the YBT posteromedial distance. Hip extensor and knee flexor strength were positively correlated with YBT posterolateral distance. [Conclusion] There was a weak correlation between lower-limb strength (hip extensors, hip abductors, and knee flexors) and dynamic postural control as measured by the YBT.

Effects of a Home Exercise Program on the Self-report Disability Index and Gait Parameters in Patients with Lumbar Spinal Stenosis

[Purpose] The present study was performed to identify the effect of a home exercise program on the self-reported disability index and gait parameters in patients with lumbar spinal stenosis (LSS). [Methods] Fifteen patients with LSS were enrolled in this study and were trained in a 4-week home exercise program (40 min/day). All patients were evaluated with three self-reported disability indices (Oswestry Disability Index, Roland-Morris Disability Questionnaire, and Spinal Stenosis Scale), and gait parameters were assessed using a GAITRite system before and after the home exercise program. [Results] Patients with LSS showed significant decreases in the self-reported questionnaire scores and pain intensity after the home exercise program. However, the gait parameters did not significantly change. [Conclusion] These findings suggest that home exercise programs can improve self-reported questionnaire scores and decrease pain in patients with LSS.

Effects of a Bridging Exercise with Hip Adduction on the EMG Activities of the Abdominal and Hip Extensor Muscles in Females

[Purpose] This study compared the activities of the abdominal and hip extensor muscles between the bridging exercise (BE) and bridging exercise with hip adduction (BEHA) positions in women using electromyography (EMG). [Subjects] We recruited 14 healthy adult females with no history of low back pain. [Methods] The subjects performed bridging exercises with and without hip adduction. The EMG activities of the rectus abdominis (RA), external oblique (EO), internal oblique (IO), and gluteus maximus (GM) muscles were recorded. [Result] The EMG activities of all muscles were significantly increased during the BEHA compared to the BE. [Conclusion] The bridging exercise with hip adduction produced greater activation of the abdominal and hip extensor muscles.

Postural taping applied to the low back influences kinematics and EMG activity during patient transfer in physical therapists with chronic low back pain

We examined the influence of the application of postural taping on the kinematics of the lumbo-pelvic-hip complex, electromyographic (EMG) activity of back extensor muscles, and the rating of perceived exertion (RPE) in the low back during patient transfer. In total, 19 male physical therapists with chronic low back pain performed patient transfers with and without the application of postural taping on the low back. The kinematics of the lumbo-pelvic-hip complex and EMG activity of the erector spinae were recorded using a synchronized 3-D motion capture system and surface EMG. RPE was measured using Borgs CR-10 scale. Differences in kinematic data, EMG activity, and RPE between the two conditions were analyzed using a paired t-test. Peak angle and range of motion (ROM) of lumbar flexion, EMG activity of the erector spinae, and RPE decreased significantly, while peak angle and ROM of pelvic anterior tilt and hip flexion increased significantly during patient transfer under the postural taping condition versus no taping (p<0.05). These findings suggest that postural taping can change back extensor muscle activity and RPE as well as the kinematics of the lumbo-pelvic-hip complex in physical therapists with chronic low back pain during patient transfer.

Acute effects of hamstring-stretching exercises on the kinematics of the lumbar spine and hip during stoop lifting.

BACKGROUND Hamstring-stretching exercises are frequently used to change lumbar spine and hip movements in the clinic. However, little research into the effects of hamstring flexibility on lumbar spine and hip movements during lifting tasks has been reported. OBJECTIVE We investigated effects of hamstring-stretching exercises on the kinematics of the lumbar spine and hip during stoop lifting. METHODS We recruited 16 males with a reduced range of motion (ROM) in active knee extension (AKE). The angle of the lumbar spine and hip was measured during stoop lifting using a 3D motion-capture system. The ROM of AKE and the angle of the lumbar spine and hip during stoop lifting between pre- and post-stretching were analyzed using a paired t-test. RESULTS We found that hamstring-stretching exercises increased the ROM of AKE significantly. After hamstring-stretching exercises, there was a significant increase in hip flexion and decreases in both lumbar flexion and the lumbar/hip flexion ratio during the preparation phase of stoop lifting. In the lifting phase, only the movement range of the hip was increased significantly. CONCLUSIONS Hamstring-stretching exercises may be useful for decreasing lumbar flexion and increasing hip flexion in people who perform repetitive stoop lifting in the workplace or during daily activities.

Relationship Between the Kinematics of the Trunk and Lower Extremity and Performance on the Y-Balance Test

The lower quarter Y‐balance test (YBT‐LQ) has been recommended as a measure of dynamic postural control in the clinical setting; however, information about the relationship between performance on the YBT‐LQ and joint kinematics is limited. Thus, the kinematic predictors responsible for performance on the YBT‐LQ need to be identified for accurate evaluation of dynamic postural control.

Patients With Low Back Pain Demonstrate Increased Activity of the Posterior Oblique Sling Muscle During Prone Hip Extension

To examine activation patterns of the myofascial chain in women experiencing chronic low back pain (CLBP) and women without CLBP during a prone hip extension (PHE) test.