Abstract:
The objective of this study is to measure tibiofemoral joint reaction force (TFJRF) during stance phase of backward and forward walking at varied speed. The participants were 54 healthy Thai male, aged 25.17 + 4.37 years, body mass index 21.15 + 1.75 kg/m². All subjects walked forward and backward on the split-belt treadmill, which could record ground reaction forces (GRF) of each foot, with 5 speeds from slowest to fastest (0.8, 1.0, 1.2, 1.4, 1.6 m/s, respectively). First direction of walking was randomized. Right GRF was used to calculate TFJRF by inverse dynamic model. In each speed of each trial, heart rate and rating of perceived exertion (RPE) were also recorded.
The results demonstrate that backward walking produced higher peak TFJRF during stance phase than forward walking in every speed. Subjects had higher heart rate and RPE in every speed when backward walking, as well. However, the average TFJRF were similar in both forward and backward walking during slow speeds (below 1.0 m/s) and lower in backward walking if speed increased more than 1.2 m/s. If compared between backward walking at 1.2 m/s, which was moderate exercise intensity (69.20 + 10.37 %HR max) and forward walking at 1.6 m/s, which was light exercise intensity (58.48 + 8.12 %HR max). The peak TFJRF were similar (135.48 ± 12.75 %BW vs. 136.73 ± 4.63 %BW), and average TFJRF were lower during backward walking (83.53 ± 1.56 %BW vs. 90.66 ± 1.56 %BW). Therefore, backward walking may produce lower TFJRF than forward walking when walk with the same exercise intensity and could be used in exercise prescriptions or rehabilitation programs for ones who have tibiofemoral joint problems.
