Walking is a recommended form of physical activity for obese adults, yet the effects of obesity and walking speed on the biomechanics of walking are not well understood. The purpose of this study was to examine joint kinematics, muscle force requirements and individual muscle contributions to the walking ground reaction forces (GRFs) at two speeds (1.25 ms(-1) and 1.50 ms(-1)) in obese and nonobese adults. Vasti (VAS), gluteus medius (GMED), gastrocnemius (GAST), and soleus (SOL) forces and their contributions to the GRFs were estimated using three-dimensional musculoskeletal models scaled to the anthropometrics of nine obese (35.0 (3.78 kg m(-2))); body mass index mean (SD)) and 10 nonobese (22.1 (1.02 kg m(-2))) subjects. The obese individuals walked with a straighter knee in early stance at the faster speed and greater pelvic obliquity during single limb support at both speeds. Absolute force requirements were generally greater in obese vs. nonobese adults, the main exception being VAS, which was similar between groups. At both speeds, lean mass (LM) normalized force output for GMED was greater in the obese group. Obese individuals appear to adopt a gait pattern that reduces VAS force output, especially at speeds greater than their preferred walking velocity. Greater relative GMED force requirements in obese individuals may contribute to altered kinematics and increased risk of musculoskeletal injury/pathology. Our results suggest that obese individuals may have relative weakness of the VAS and hip abductor muscles, specifically GMED, which may act to increase their risk of musculoskeletal injury/pathology during walking, and therefore may benefit from targeted muscle strengthening.
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机译：步行是肥胖成年人的一种体育锻炼方式，但肥胖和步行速度对步行生物力学的影响尚不十分清楚。这项研究的目的是检查肥胖和非肥胖成年人在两种速度（1.25 ms（-1）和1.50 ms（-1））下的关节运动学，肌肉力量要求和单个肌肉对步行地面反作用力（GRF）的贡献。 Vasti（VAS），臀中肌（GMED），腓肠肌（GAST）和比目鱼肌（SOL）的力及其对GRF的贡献是使用三维肌肉骨骼模型根据9个肥胖症的人体测量学（35.0（3.78 kg m（ -2）））;体重指数平均值（SD））和10位非肥胖（22.1（1.02 kg m（-2）））受试者。肥胖者在早期站立时笔直的膝盖以较快的速度行走，而在这两种速度下单肢支撑时骨盆的倾斜度更大。肥胖成年人和非肥胖成年人的绝对力要求通常更高，主要例外是VAS，两组之间的相似。在这两种速度下，肥胖组的GMED瘦体重（LM）归一化力输出都更大。肥胖个体似乎采取步态模式，这会降低VAS力输出，尤其是在速度大于其首选步行速度的情况下。肥胖个体中相对较高的GMED相对力需求可能会导致运动学改变以及肌肉骨骼损伤/病理的风险增加。我们的结果表明，肥胖的人可能具有VAS和髋外展肌的相对无力，特别是GMED，这可能会增加他们在行走过程中发生肌肉骨骼损伤/病理的风险，因此可以受益于有针对性的肌肉强化。
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