Effects of obesity on the biomechanics of walking at different speeds
Effects of obesity on the biomechanics of walking at different speeds
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DOI：
10.1249/mss.0b013e318076b54b
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发表时间：
2007-09-01
期刊：
影响因子：
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通讯作者：
Kram, Rodger
中科院分区：
文献类型：
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作者：
Browning, Raymond C.;Kram, Rodger
目的：步行是治疗肥胖症的一种推荐运动形式，但步行可能是将肥胖与肌肉骨骼病理，特别是膝关节骨关节炎联系起来的生物力学负荷的关键来源。我们假设，与正常体重的成年人相比，1)肥胖成年人在步行过程中会有更大的绝对地面反作用力(GRF)，但在较慢的步行速度下，他们的GRF会减少；2)在给定的步行速度下，肥胖成年人会有更大的矢状面绝对腿关节力矩，但这些力矩在较慢的步速下会减少。方法：我们测量了20名成年人(肥胖者和正常体重各10名)以6种速度(0.5-1.75毫秒/秒)在水平测力跑步机上行走时的GRF和矢状面运动学。我们计算了臀部、膝盖和脚踝的矢状面净肌力矩。结果：与正常体重的同龄人相比，肥胖者的绝对GRT(N)、立位相矢状面净肌力矩(N.M)和步幅(M)都要大得多。结论：肥胖者的膝关节矢状面力矩较大，表明他们比正常体重的成年人行走时膝关节负荷更大。慢走会减少GRF和净肌肉时刻，对于希望步行锻炼的肥胖成年人来说，这可能是一种降低风险的策略。当肥胖受试者步行速度为1.0毫秒(-1)而不是1.5毫秒(-1)时，膝关节矢状面峰值力矩减少45%。当肥胖受试者以大约1.1毫秒(-1)的速度行走时，他们以1.4毫秒(-1)的典型首选速度行走时，他们具有与正常体重受试者相同的矢状面膝关节网肌力矩的绝对峰值。
Purpose: Walking is a recommended form of exercise for the treatment of obesity, but walking may be a critical source of biomechanical loads that link obesity and musculoskeletal pathology, particularly knee osteoarthritis. We hypothesized that compared with normal-weight adults 1) obese adults would have greater absolute ground-reaction forces (GRF) during walking, but their GRF would be reduced at slower walking speeds; and 2) obese adults would have greater sagittal-plane absolute leg-joint moments at a given walking speed, but these moments would be reduced at slower walking speeds. Methods: We measured GRF and recorded sagittal-plane kinematics of 20 adults (10 obese and 10 normal weight) as they walked on a level, force-measuring treadmill at six speeds (0.5-1.75 m.s(-1)). We calculated sagittal-plane net muscle moments at the hip, knee, and ankle. Results: Compared with their normal-weight peers, obese adults had much greater absolute GRT (N), stance-phase sagittal-plane net muscle moments (N.m) and step width (m). Conclusions: Greater sagittal-plane knee moments in the obese subjects suggest that they walked with greater knee-joint loads than normal-weight adults. Walking slower reduced GRF and net muscle moments and may be a risk-lowering strategy for obese adults who wish to walk for exercise. When obese subjects walked at 1.0 versus 1.5 m.s(-1), peak sagittal-plane knee moments were 45% less. Obese subjects walking at approximately 1.1 m.s(-1) would have the same absolute peak sagittal-plane knee net muscle moment as nor-mal-weight subjects when they walk at their typical preferred speed of 1.4 m.s(-1).