Effect of Adapted Ergometer Setup and Rowing Speed on Lower Extremity Loading in People with and without Spinal Cord Injury

Abstract

Introduction: Functional electrical stimulation assisted rowing (FES rowing) on an adapted ergometer is used in spinal cord injury (SCI) rehabilitation. A primary goal is to mechanically load the lower extremity to prevent disuse osteoporosis. Recent studies reported the small foot reaction force in FES rowing was not sufficient to prevent bone loss. Objective: This study aims to investigate the effect of ergometer setup and rowing speed on lower extremity loading in able-bodied and SCI individuals. Design: Twenty able-bodied novice rowers and one experienced SCI rower rowed on an adapted ergometer with different speeds and setups. Motion capture system and force sensors were used to calculate forces and moments at the knee. Main Outcome Measures: Foot reaction force and knee moment for all participants, and tibiofemoral force of the SCI rower. Results: Peak foot reaction forces of able-bodied rowers ranged from 0.28 to 0.45 body weights (BW), which was less than half the force in normal rowing. A fast rowing speed, forward seat position, and large knee RoM were associated with higher foot force and knee moment during able-bodied rowing. The SCI subject had the greatest foot reaction force (0.40 BW) when rowing with small knee RoM at a rear seat position and the highest tibiofemoral force (2.23 BW) with large knee RoM at a rear seat position. Conclusion: Ergometer setup and speed can double the force generation at the foot during both able-bodied rowing and FES-rowing. Rowing forms (range of motion and speed) that resulted in the greatest foot reaction force were different for able-bodied rowers and SCI rowers, indicating a trade-off between motion and force generation in FES-rowing that warrants further investigation with more SCI rowers. Clinicians and physical therapist should be aware that ergometer setups can be easily adjusted to modify rowing forms and loading patterns of users with SCI.