2019, Vol.14, No.3

Journal of the Korean Society of Physical Medicine 2023 KCI Impact Factor : 0.45

pISSN : 1975-311X / eISSN : 2287-7215
https://journal.kci.go.kr/kspm

PURPOSE: This study compared the changes in the range of motion (ROM) on the knee joint according to three different isometric contraction intensities when applying Evjenth-Hamberg stretching (EHS) to the hamstring muscles of healthy subjects. METHODS: Forty eight healthy subjects aged between 20 and 39 years were allocated randomly to four groups; performing EHS at 10% maximum voluntary isometric contraction (MVIC) group, EHS at 50% MVIC group, EHS at 100% MVIC group, and control group (CG) pre-, and post-intervention. The flexibility of the hamstring muscles was evaluated using a digital goniometer for measuring the knee joint ROM motion. A Chattanooga stabilizer was used to adjust the MVIC intensity by 10%, 50%, and 100%, respectively. RESULTS: These results show that the pre- and post-intervention knee joint ROM were significantly different in all four groups (p<.05). The post-intervention knee joint ROM showed a significant difference between the 100% MVIC group and non-MVIC group (p<.05). The knee joint ROM difference between the pre- and post-interventions was similar in the 10% MVIC and 50% MVIC groups but significant differences were observed among the other groups (p<.05). CONCLUSION: EHS of the hamstring muscles was effective in improving the knee joint ROM with an isometric contraction intensity of 10%, 50%, or 100% MVIC, and of these, 100% MVIC was most effective.

PURPOSE: Sitting with crossed legs may have an effect on maintaining a healthy body posture and proper functioning of the respiratory system. Thus, this study’s objective was to identify whether or not sitting with crossed legs affects the vertebral angle, chest wall mobility, the pulmonary function, and the activity of the respiratory muscles. METHODS: Thirty healthy subjects were recruited for this study (16 males and 14 females). The vertebral angle, chest wall mobility, pulmonary function, and the activity of the respiratory muscle were measured while the subjects sat in the correct posture and these factors were again measured with the subjects seated with their legs crossed. Three-dimensional motion analysis was used to determine the trunk and lumbar vertebral angles. Surface electromyography was employed to measure the sternocleidomastoid, the rectus abdominis, and the external and internal oblique abdominis muscles. A tapeline was utilized to evaluate the subjects’ chest wall mobility. Spirometry was assessed to determine the forced vital capacity and forced expiratory volume in one second. Paired t-tests were then performed (p<.05). RESULTS: There were significant differences in the trunk and lumbar flexion angles, the chest wall mobility, the activity of the right external oblique muscle, and the left internal oblique abdominis muscle. However, the difference in pulmonary function did not reach statistical significance. CONCLUSION: A crossed leg posture caused slight thoracic extension and lumbar flexion, which may lead to a decrease of the chest wall mobility and also to an imbalance of the abdominal muscles. Therefore, sitting with a crossed leg posture should be avoided. Yet a crossed leg posture did not have any clinical effect on the pulmonary function of healthy people. It may be necessary to study the effects of sitting with crossed legs over an extended period of time for patients suffering with impaired respiratory function.

PURPOSE: This study examined the changes in the kinematic variables during walking on a downhill ramp according to the shoe heel height. METHODS: The subjects were 10 adult women with no history of musculoskeletal disorders who agreed to participate in the study. Data were collected using a motion analysis system (VICON) consisting of six infrared cameras. The slope was 120 ㎝ in width, 200 ㎝ in length, and 15 in inclination. To confirm the change in gait parameters (stride length, gait speed) and lower extremity joint angle according to the heel heights of the shoes, flat, 5 ㎝, and 10 ㎝ heel shoes were prepared and walked alternately. RESULTS: As a result, both the stride length and walking speed showed significant differences according to the heel height between flat and 10 ㎝ (p<.05). In the sagittal plane, there was no significant difference in the hip joint and knee joint, but a significant difference was observed in all events in the ankle joint on all heel heights (p<.05). In particular, the heel strike and mid stance events showed significant differences among all height conditions (p<.05). No significant difference was observed in any of the joint angle changes in the frontal plane (p>.05). CONCLUSION: As the shoe heel height increased, the instability increased and efforts to secure the stability were made, leading to a shortened stride length, walking speed, and angle of the ankle joint.