Multi-joint foot kinetics during walking in people with Diabetes Mellitus and peripheral neuropathy

Neuropathic tissue changes can alter muscle function and are a primary reason for foot pathologies in people with Diabetes Mellitus and peripheral neuropathy (DMPN). Understanding of foot kinetics in people with DMPN is derived from single-segment foot modeling approaches. This approach, however, does not provide insight into midfoot power and work. Gaining an understanding of midfoot kinetics in people with DMPN prior to deformity or ulceration may help link foot biomechanics to anticipated pathologies in the midfoot and forefoot. The purpose of this study was to evaluate midfoot (MF) and rearfoot (RF) power and work in people with DMPN and a healthy matched control group. Thirty people participated (15 DMPN and 15 Controls). An electro-magnetic tracking system and force plate were used to record multi-segment foot kinematics and ground reaction forces during walking. MF and RF power, work, and negative work ratios were calculated and compared between groups. Findings demonstrated that the DMPN group had greater negative peak power and reduced positive peak power at the MF and RF (all p≤0.05). DMPN group negative work ratios were also greater at the MF and RF [Mean difference MF: 9.9%; p=0.24 and RF: 18.8%; p<0.01]. In people with DMPN, the greater proportion of negative work may negatively affect foot structures during forward propulsion, when positive work and foot stability should predominate. Further study is recommended to determine how both MF and RF kinetics influence the development of deformity and ulceration in people with DMPN.