The primary purpose of this research was to determine the effect of ankle joint mobility and strength (plantar flexor peak torque) on kinetic variables (ground reaction forces, joint moments, joint power) measured during walking. A secondary purpose was to compare the walking pattern of subjects with diabetes and peripheral neuropathy to age matched controls. Hypotheses were based on predictions from a two-dimensional, link-segment model. Ten subjects (mean age=58 years) with peripheral neuropathy secondary to diabetes mellitus (DM) and 10 nondiabetic (NODM) subjects (mean age=57 years) were evaluated. The following data were collected on all subjects:​ ankle joint mobility measured with a goniometer, plantar flexion peak torque measured with an isokinetic dynamometer, kinematics of the trunk and lower extremity during walking measured with an automated video analysis system, and simultaneous ground reaction forces measured with a force platform. Moments of force and power at the ankle, knee, and hip were calculated using a link—segment model. Data were analyzed using multiple regression analysis and canonical correlation. Differences between groups were determined using a t-test.

Ankle strength and mobility showed an association with ground reaction forces in the anterior-posterior direction, ankle moments, and ankle power. In general, ankle strength showed a greater contribution to kinetic variables than ankle mobility. The DM subjects showed less ankle mobility, ankle moment, ankle power, walking velocity, and stride length than the NODM subjects during walking. The DM subjects tended to pull their leg forward using hip flexor muscles (hip strategy) rather than pushing their leg forward using plantar flexor muscles (ankle strategy) compared to the NODM subjects. These changes in the walking pattern of the DM subjects appeared to be due primarily to the significant decrease in strength and mobility at the ankle joint compared to the NODM group. Obtained values were consistent with a priori hypotheses providing evidence that the link—segment model can be useful in understanding the mechanical aspects of various movements including walking.