Kyue-Nam Park

Effects of the Abdominal Drawing-In Maneuver on Muscle Activity, Pelvic Motions, and Knee Flexion During Active Prone Knee Flexion in Patients With Lumbar Extension Rotation Syndrome

OBJECTIVE To investigate the effects of performing an abdominal drawing-in maneuver (ADIM) during active prone knee flexion on the hamstrings and erector spinae muscle activity, the amounts of pelvic motion and knee flexion, and onset of pelvic movements. DESIGN Comparative, repeated-measures study. SETTING University research laboratory. PARTICIPANTS Men patients (N=18) with lumbar extension rotation syndrome. INTERVENTION Subjects performed prone knee flexion in 2 conditions. MAIN OUTCOME MEASURES To measure muscle activity, surface electromyogram (EMG) of both erector spinae and the medial and lateral hamstrings was performed. Kinematic data on the pelvic motion and knee flexion were measured using a 3-dimensional motion analysis system. Repeated 1-way analysis of variance was used for the statistical analysis. RESULTS Significantly decreased electromyographic activity in the right and left erector spinae and significantly increased electromyographic activity in the medial and lateral hamstrings activity were shown during prone knee flexion in ADIM condition using the pressure biofeedback unit. In addition, the amounts of anterior pelvic tilt, pelvic rotation, knee flexion, and perceived pain decreased significantly during prone knee flexion in the ADIM condition compared with the same maneuver in the non-ADIM condition. The onset of anterior pelvic tilt and pelvic rotation occurred significantly earlier in the non-ADIM condition, compared with the ADIM condition. CONCLUSIONS ADIM effectively increased activation of knee flexors, decreased activation of back extensors, and reduced the pelvic motions and low back pain during prone knee flexion in patients with lumbar extension rotation syndrome.

Effects of the pelvic rotatory control method on abdominal muscle activity and the pelvic rotation during active straight leg raising

The aim of this study was to examine the effects of the pelvic rotatory control method on abdominal muscle activity and the amount of pelvic rotation while maintaining active straight leg raising (ASLR) at the level of the target bar. In this study, 27 healthy female volunteers were instructed to perform ASLR, ASLR with a pelvic compression belt, and ASLR with the pelvic rotatory control method. Surface electromyography (EMG) data were collected from the bilateral rectus abdominis (RA), external oblique abdominis (EO), and internal oblique abdominis (IO) muscles, and angles of pelvic rotation were measured using a 3-dimensional motion-analysis system. EMG activity of all abdominal muscles was greater and pelvic rotation was less in the pelvic rotatory control method compared with both the conventional ASLR method and the ASLR with pelvic compression belt method (p < 0.05). The findings suggest that ASLR with the pelvic rotatory control method is effective in activating the abdominal muscles and minimizing unwanted lumbopelvic rotation during ASLR exercise.

Comparison of electromyographic activity of the lower trapezius and serratus anterior muscle in different arm-lifting scapular posterior tilt exercises

OBJECTIVE To determine the most effective exercise to specifically activate the scapular posterior tilting muscles by comparing muscle activity generated by different exercises (wall facing arm lift, prone arm lift, backward rocking arm lift, backward rocking diagonal arm lift). DESIGN Repeated-measure within-subject intervention. PARTICIPANTS The subjects were 20 healthy young men and women. MAIN OUTCOME MEASURES Lower trapezius (LT) and serratus anterior (SA) muscle activity was measured when subjects performed the four exercises. RESULTS Muscle activity was significantly different among the four exercise positions (p<0.05). The backward rocking diagonal arm lift elicited significantly greater activity in the LT muscle than did the other exercises (p<0.05). The backward rocking arm lift showed significantly more activity in the SA muscle than did the other exercises (p<0.05). CONCLUSIONS Clinicians can use these results to develop scapular posterior tilting exercises that specifically activate the target muscle.

Selective Activation of the Infraspinatus Muscle

CONTEXT To improve selective infraspinatus muscle strength and endurance, researchers have recommended selective shoulder external-rotation exercise during rehabilitation or athletic conditioning programs. Although selective strengthening of the infraspinatus muscle is recommended for therapy and training, limited information is available to help clinicians design a selective strengthening program. OBJECTIVE To determine the most effective of 4 shoulder external-rotation exercises for selectively stimulating infraspinatus muscle activity while minimizing the use of the middle trapezius and posterior deltoid muscles. DESIGN Cross-sectional study. SETTING University research laboratory. PATIENTS OR OTHER PARTICIPANTS A total of 30 healthy participants (24 men, 6 women; age = 22.6 ± 1.7 years, height = 176.2 ± 4.5 cm, mass = 65.6 ± 7.4 kg) from a university population. INTERVENTION(S) The participants were instructed to perform 4 exercises: (1) prone horizontal abduction with external rotation (PER), (2) side-lying wiper exercise (SWE), (3) side-lying external rotation (SER), and (4) standing external-rotation exercise (STER). MAIN OUTCOME MEASURE(S) Surface electromyography signals were recorded from the infraspinatus, middle trapezius, and posterior deltoid muscles. Differences among the exercise positions were tested using a 1-way repeated-measures analysis of variance with Bonferroni adjustment. RESULTS The infraspinatus muscle activity was greater in the SWE (55.98% ± 18.79%) than in the PER (46.14% ± 15.65%), SER (43.38% ± 22.26%), and STER (26.11% ± 15.00%) (F3,87 = 19.97, P < .001). Furthermore, the SWE elicited the least amount of activity in the middle trapezius muscle (F3,87 = 20.15, P < .001). Posterior deltoid muscle activity was similar in the SWE and SER but less than that measured in the PER and STER (F3,87 = 25.10, P < .001). CONCLUSIONS The SWE was superior to the PER, SER, and STER in maximizing infraspinatus activity with the least amount of middle trapezius and posterior deltoid activity. These findings may help clinicians design effective exercise programs.

Lower Extremity Strength and the Range of Motion in Relation to Squat Depth

Abstract The purpose of this study was to determine which variables of the range of motion (ROM) and strength of the hip, and ankle are associated with squat depth. In total, 101 healthy subjects (64 males, 37 females) participated in the study. Outcome measures consisted of the ROM of hip flexion, hip internal rotation, external rotation, ankle dorsiflexion with an extended and flexed knee joint, and strength of the hip flexor and ankle dorsiflexor. Squat depth was measured using SIMI motion analysis software. Pearson correlation was used to determine the relationship between variables and squat depth. Multiple stepwise regression analysis was performed to determine variables associated with squat depth. The multiple regression model indicated that ankle dorsiflexion with a flexed knee and the hip flexion ROM were significantly associated with squat depth in male subjects (R2 = 0.435) and ankle dorsiflexion with an extended knee and dorsiflexor strength were significantly associated with squat depth in female subjects (R2 = 0.324). Thus, exercises to increase the ROM of the ankle dorsiflexion, hip flexion, and dorsiflexor strength can be recommended to improve squat performance. Future studies should assess an increased ROM of the ankle dorsiflexion, hip flexion, or dorsiflexor strength effect on deep squat performance.

Effect of feedback techniques for lower back pain on gluteus maximus and oblique abdominal muscle activity and angle of pelvic rotation during the clam exercise

OBJECTIVES This study was conducted in order to determine the effect of feedback tools on activities of the gluteus maximus (Gmax) and oblique abdominal muscles and the angle of pelvic rotation during clam exercise (CE). DESIGN Comparative study using repeated measures. SETTING University laboratory. PARTICIPANTS Sixteen subjects with lower back pain. MAIN OUTCOME MEASURES Each subject performed the CE without feedback, the CE using a pressure biofeedback unit (CE-PBU), and the CE with palpation and visual feedback (CE-PVF). Electromyographic (EMG) activity and the angles of pelvic rotation were measured using surface EMG and a three-dimensional motion-analysis system, respectively. One-way repeated-measures ANOVA followed by the Bonferroni post hoc test were used to compare the EMG activity in each muscle as well as the angle of pelvic rotation during the CE, CE-PBU, and CE-PVF. RESULTS The results of post-hoc testing showed a significantly reduced angle of pelvic rotation and significantly more Gmax EMG activity during the CE-PVF compared with during the CE and CE-PBU. CONCLUSION These findings suggest that palpation and visual feedback is effective for activating the Gmax and controlling pelvic rotation during the CE in subjects with lower back pain.

Influence of Thoracic Flexion Syndrome on Proprioception in the Thoracic Spine

[Purpose] This study was performed to determine the difference in thoracic repositioning sense in young people with and without thoracic flexion syndrome (TFS) in target positions of half extension. [Subjects] People with TFS (n = 15; 7 men and 8 women) and people without TFS (n = 15; 7 men and 8 women) were recruited from three universities. Subjects were guided into a sitting extension target posture and were asked to move from a neutral position (2 s) to an extension target position (2 s); 10 trials were performed. [Results] People with TFS showed a significantly higher thoracic repositioning error in the extension target position than people without TFS. [Conclusion] People with TFS show a higher thoracic spine repositioning error in extension than people without TFS. A rehabilitation program to treat TFS should be implemented for individuals with decreased position sense of the thoracic spine.

Effects of Motor Control Exercise Vs Muscle Stretching Exercise on Reducing Compensatory Lumbopelvic Motions and Low Back Pain: A Randomized Trial

OBJECTIVES The purpose of this study was to investigate the effectiveness of a 6-week motor control exercise (MCE) vs stretching exercise (SE) on reducing compensatory pelvic motion during active prone knee flexion (APKF) and intensity of low back pain. METHODS Thirty-six people in the lumbar-rotation-extension subgroup were randomly assigned equally into 2 exercise groups (18 people in each an MCE or SE group). A 3-dimensional motion-analysis system was used to measure the range and onset time of pelvic motion and knee flexion during APKF. Surface electromyography was used to measure the muscle activity and onset time of the erector spinae and the hamstrings during APKF. The level of subjective low back pain was measured using a visual analog scale. RESULTS The MCE group had more significant decreases in and delay of anterior pelvic tilt, pelvic rotation, and erector spinae muscle activity during APKF, as well as reduced intensity of low back pain compared with the SE group (P < .05). CONCLUSIONS For rehabilitation in patients in the lumbar-rotation-extension subgroup, MCE was more effective than SE in reducing compensatory pelvic motion and muscle activity during APKF and minimizing low back pain.

Influence of Wearing a Brassiere on Pain and EMG Activity of the Upper Trapezius in Women with Upper Trapezius Region Pain.

[Purpose] This study examined the effect of wearing a brassiere on upper trapezius (UT) region pain and EMG activity during arm elevation by women. [Subjects and Methods] Fourteen healthy women were recruited. Surface EMG data were collected from the UT muscles during arm elevation. Pressure pain in the UT region was measured using a baseline dolorimeter. [Results] The EMG activity of the UT increased significantly when a brassiere was worn compared to without. UT region pain showed no significant difference between with and without wearing a brassiere. [Conclusion] This suggests that wearing a brassiere increases the muscle activation of the UT in women.

Comparison of erector spinae and hamstring muscle activities and lumbar motion during standing knee flexion in subjects with and without lumbar extension rotation syndrome

The aim of this study was to compare the activity of the erector spinae (ES) and hamstring muscles and the amount and onset of lumbar motion during standing knee flexion between individuals with and without lumbar extension rotation syndrome. Sixteen subjects with lumbar extension rotation syndrome (10 males, 6 females) and 14 healthy subjects (8 males, 6 females) participated in this study. During the standing knee flexion, surface electromyography (EMG) was used to measure muscle activity, and surface EMG electrodes were attached to both the ES and hamstring (medial and lateral) muscles. A three-dimensional motion analysis system was used to measure kinematic data of the lumbar spine. An independent-t test was conducted for the statistical analysis. The group suffering from lumbar extension rotation syndrome exhibited asymmetric muscle activation of the ES and decreased hamstring activity. Additionally, the group with lumbar extension rotation syndrome showed greater and earlier lumbar extension and rotation during standing knee flexion compared to the control group. These data suggest that asymmetric ES muscle activation and a greater amount of and earlier lumbar motion in the sagittal and transverse plane during standing knee flexion may be an important factor contributing to low back pain.