In vivo muscle morphology comparison between walking with and without ankle-foot orthosis in healthy adults. : A feasibility cross over study.

Abstract: Background:People who have survived a stroke often have post-stroke complications. One common complication is muscle weakness in the lower extremities. To treat this, patients can use an ankle-foot orthosis (AFO). The purpose of this study was to investigate muscle morphology in the quadriceps when walking with an AFO. Method:This feasibility cross over study was made on 7 healthy adults. To measure the morphology, an SMG device was used. The device measured muscle area change, EMG -and MMG activation, knee angle and plantar forces. Statistical analyzes was made for all measured data except knee angle.  Result:The area of the quadriceps was significantly smaller when walking with the AFO in mid-swing phase than without (p=0,035). A significant reduction in force could also be found under the MTP1 (p=0,016) and under the calcaneus (p=0,042) in toe off (60%). The result did not show any significant differences in initial contact (p=0,617), mid stance (p=0,287), toe off (p=0,527) or terminal swing (p=0,712) for muscle area change of quadriceps, or plantar force at MTP5 in toe off (p=0,704). Conclusion:The results suggest that the subjects needed to work more with the quadriceps muscles when walking with the AFO. More studies are needed to reach clinical relevance.