Muscle Forces and Their Contributions to Vertical and Horizontal Acceleration of the Center of Mass During Sit-to-Stand Transfer in Young, Healthy Adults

作者：Caruthers Elena J; Thompson Julie A; Chaudhari Ajit M W; Schmitt Laura C; Best Thomas M; Saul Katherine R; Siston Robert A^*

来源：Journal of Applied Biomechanics, 2016, 32(5): 487-503.

DOI：10.1123/jab.2015-0291

• musculoskeletal modeling
• OpenSim
• knee

Sit-to-stand transfer is a common task that is challenging for older adults and others with musculoskeletal impairments. Associated joint torques and muscle activations have been analyzed two-dimensionally, neglecting possible three-dimensional (3D) compensatory movements in those who struggle with sit-to-stand transfer. Furthermore, how muscles accelerate an individual up and off the chair remains unclear; such knowledge could inform rehabilitation strategies. We examined muscle forces, muscle induced accelerations, and interlimb muscle force differences during sit-to-stand transfer in young, healthy adults. Dynamic simulations were created using a custom 3D musculoskeletal model; static optimization and induced acceleration analysis were used to determine muscle forces and their induced accelerations, respectively. The gluteus maximus generated the largest force (2009.07 +/- 277.31 N) and was a main contributor to forward acceleration of the center of mass (COM) (0.62 +/- 0.18 m/s(2)), while the quadriceps opposed it. The soleus was a main contributor to upward (2.56 +/- 0.74 m/s(2)) and forward acceleration of the COM (0.62 +/- 0.33 m/s(2)). Interlimb muscle force differences were observed, demonstrating lower limb symmetry cannot be assumed during this task, even in healthy adults. These findings establish a baseline from which deficits and compensatory strategies in relevant populations (eg, elderly, osteoarthritis) can be identified.

• 出版日期2016-10