Evaluation of predicted knee‐joint muscle forces during gait using an instrumented knee implant

Abstract

Musculoskeletal modeling and optimization theory are often used to determine muscle forces in vivo. However, convincing quantitative evaluation of these predictions has been limited to date. The present study evaluated model predictions of knee muscle forces during walking using in vivo measurements of joint contact loading acquired from an instrumented implant. Joint motion, ground reaction force, and tibial contact force data were recorded simultaneously from a single subject walking at slow, normal, and fast speeds. The body was modeled as an 8-segment, 21-degree-of-freedom articulated linkage, actuated by 58 muscles. Joint moments obtained from inverse dynamics were decomposed into leg-muscle forces by solving an optimization problem that minimized the sum of the squares of the muscle activations. The predicted knee muscle forces were input into a 3D knee implant contact model to calculate tibial contact forces. Calculated and measured tibial contact forces were in good agreement for all three walking speeds. The average RMS errors for the medial, lateral, and total contact forces over the entire gait cycle and across all trials were 140 AE 40 N, 115 AE 32 N, and 183 AE 45 N, respectively. Muscle coordination predicted by the model was also consistent with EMG measurements reported for normal walking. The combined experimental and modeling approach used in this study provides a quantitative framework for evaluating model predictions of muscle forces in human movement. ß

Muscular strategy shift in human running: dependence of running speed on hip and ankle muscle performance

“…Musculoskeletal modelling is a powerful tool for studying muscle function during movement because it allows individual muscle outputs such as length, force and power to be determined noninvasively (Pandy and Andriacchi, 2010). The accuracy of the model used to calculate lower-limb muscle forces during running has been evaluated in a number of previous studies undertaken by various groups (Erdemir et al, 2007;Hamner et al, 2010;Kim et al, 2009;Pandy and Andriacchi, 2010). Further, muscle morphological parameters assumed in the model were updated with the most recent data obtained from a comprehensive cadaver dissection study (Ward et al, 2009).…”

A Novel Experimental Knee-Pain Model Affects Perceived Pain and Movement Biomechanics

“…34 Reduced plantar-flexion and knee-extension moments have also been associated with decreased axial kneejoint contact forces. 19,35 Axial knee-joint contact force peaks twice during the stance phase of gait, at approximately 15% and 50% of the gait cycle. 19,35 The vastii and gastrocnemius muscles are the primary contributors to the first and second peaks, respectively.…”

“…19,35 Axial knee-joint contact force peaks twice during the stance phase of gait, at approximately 15% and 50% of the gait cycle. 19,35 The vastii and gastrocnemius muscles are the primary contributors to the first and second peaks, respectively. 15,19 As the vastii are associated with the first knee-extension moment peak, 15,19 the observed decrease for knee-extension moment may indicate reduced vastii activity in an attempt to decrease knee-joint load.…”

Relationship between muscle forces, joint loading and utilization of elastic strain energy in equine locomotion

“…The locations of the joint centers and orientations of the joint axes in the model were found by minimizing differences between the positions of surface markers located on the subject and virtual markers defined in the model (Kim et al, 2009;Reinbolt et al, 2005). Muscle-tendon lengths were scaled using ratios found by dividing inter-marker distances obtained from the kinematic measurements by inter-marker distances determined from a generic marker set defined for the model.…”

“…We calculated 210 and 190% of body weight (10.6 and 9.7kN, respectively) as the mean peak forces transmitted by the P1-MC3 and Ses-MC3 joints, respectively, during walking. Human hip joint forces in walking have been measured to be 238-471% of body weight (1.99-3.06 kN) (Bergmann et al, 2001;Bergmann et al, 1993), whereas knee joint forces in walking have been measured (Kim et al, 2009) and calculated (Shelburne et al, 2006) to be approximately 270% of body weight (1.75-2.02 kN). Because the contact areas in the equine MCP joint are not significantly larger than those in other species, whereas the contact forces are evidently much higher, the mean joint contact stress is likely to be much higher.…”