Biomechanical Adjustments in Lumbar Spine Associated with Sudden Upper Limb Loading. |
Park, Kwang Hong , Hwang, Ji Hye , Lee, Yong Taek , Park, Won Hah , Roh, Kyung Sun , Kwon, Tae Kyu |
1Department of Physical Medicine and Rehabilitation, Samsung Medical Center, Sungkyunkwan University School of Medicine, Korea. hwanglee@smc.samsung.co.kr 2Division of Sports Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Korea. 3Department of Ergonomic Therapy, The Graduate School of Health and Environment, Yonsei University, Korea. 4Division of Bionics and Bioinformatics, Chonbuk National University, Korea. |
상지에 갑자기 가해진 하중에 대한 요추의 생체역학적 반응 |
박광홍, 황지혜, 이용택, 박원하1, 노경선2, 권대규3 |
성균관대학교 의과대학 재활의학교실, 1삼성서울병원 스포츠의학센터, 2연세대학교 인간공학치료학부, 3전북대학교 생체정보공학부 |
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Abstract |
Objective To investigate the response of back muscle, the flexion moment and the kinematic change of lumbar spine during sudden upper limb loading between expected and unexpected conditions. Method 23 healthy young subjects (13 male and 10 female, mean age 26.6±3.3) were recruited. We measured the latency of paraspinal muscle contraction (erector spinae and lumbar multifidus), flexion moment of lumbar spine, and kinematic change of lumbar spine during sudden upper limb loading by using surface EMG system, motion analysis system, and force platform. 6 trials with 3 eye opened and 3 eye closed were performed randomly. Results The latency of paraspinal muscle contractions was significantly slower during eyes closed condition than during eyes opened condition after sudden upper limb loading (p<0.05). The flexion moment and the flexion change of lumbar spine increased significantly during eyes closed condition compared with eyes opened condition (p<0.05). Conclusion The response of paraspinal muscle was significantly slower and the flexion moment and the flexion change of lumbar spine was higher during unexpected condition than during expected condition after sudden upper limb loading. Therefore, the spinal stability is more decreased during unexpected condition than expected condition. (J Korean Acad Rehab Med 2007; 31: 718-724) |
Key Words:
Lumbar spine, Biomechanical muscle reaction, Load bearing |
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