Design and analysis of an original powered foot clearance creator mechanism for walking in patients with spinal cord injury

Background: The aim of this study was to assess the performance of an original powered foot clearance creator (PFCC) mechanism worn in conjunction with an isocentric reciprocal gait orthosis (IRGO) and evaluate its effect on trunk compensatory movements and spatiotemporal parameters in nine healthy subjects.

Method: A PFCC motorized mechanism was designed that incorporated twin sole plates, the movements of which enabled increased toe to floor clearance during swing phase. A prototype was constructed in combination with an IRGO, and hence was re-named as an IRGO-PFCC orthosis. The effects of IRGO-PFCC usage on the spatiotemporal parameters and trunk compensatory movements during walking were then analyzed under two conditions, firstly with the PFCC ‘active’ i.e., with the motorized device functioning, and secondly inactive, where floor clearance was standard.

Results: Ambulating with IRGO-PFCC orthosis resulted in reduction in the spatiotemporal parameters of gait (speed of walking, cadence and stride length) in nine healthy subjects. Walking with IRGO-PFCC orthosis led to significant differences in lateral (p?=?.007) and vertical (p?=?.008) trunk compensatory movements. In other words, through using IRGO-PFCC orthosis, the lateral and vertical trunk compensatory movements decreased by 51.32% and 42.7%, respectively.

Conclusion: An adapted PFCC mechanism, with a relatively small motor and power supply could effectively increase toe to floor clearance during swing phase and thereby decrease trunk compensatory motions and potentially improve energy consumption.

• Implications for rehabilitations

• ?The High rejection rates of reciprocal gait orthoses are related to the increasing in energy expenditure and burden loads on the upper limb joints during walking following trunk compensatory movements.?An original powered foot clearance creator mechanism was designed and constructed to assisting floor clearance capability and reduce trunk compensatory movements in subjects with spinal cord injury during swing phase of gait.?This original powered foot clearance creator mechanism by using moveable soleplates and motorized actuation could decrease the trunk compensatory motions during the ambulation of nine healthy subjects.?More experiments are needed to investigate this mechanism on trunk compensatory movements of SCI subjects.