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Context: Motorized treadmills (MTs) present an altered motor task compared to overground (OG) locomotion in that MT belt surfaces are motor-driven, whereas individuals walking/running OG must propel themselves. A possible solution may lie with novel nonmotorized treadmill (NMT) devices as the belt surface is propelled by the user. Objective: The purpose of this study was to compare gait performance during both MT and NMT locomotion to OG. Design: Crossover study. Setting: A university research laboratory. Patients: A total of 20 healthy adults (10 women) participated in the study. Intervention: Each participant performed self-selected walking and running OG, and on both an MT and NMT. Main Outcome Measure: Shoulder, trunk, and lower-extremity kinematics were analyzed for each treadmill condition and compared to OG. Results: The analyses demonstrated that there were no differences between MT and OG gait kinematics during either walking or running. However, NMT gait showed increased hip, knee, and ankle flexions in late swing and early stance compared to OG during both walking and running. For example, during walking, the NMT elicited hip-, knee-, and ankle-flexion/extension angles of 34.7°, 8.0°, and 3.6° at foot strike compared to 24.8°, −3.1°, and −5.8° in the OG condition (P < .05). There was also a significant reduction in trunk-flexion/extension range of motion during running compared to OG (7.7° in NMT vs 9.8° in OG). Conclusions: These differences may have implications for both training and rehabilitation on an NMT. Future studies should consider the influence of NMT familiarization on gait performance and should emphasize the assessment of neuromuscular performance.
Fullenkamp, Laurent, Campbell, and Cripps are with Exercise Science Program, School of Human Movement, Sport, & Leisure Studies, Bowling Green State University, Bowling Green, OH. Tolusso is with the Department of Kinesiology, University of Alabama, Tuscaloosa, AL.