Biomechanics of Walking in Healthy Adults at Different Gait Speeds

Abstract

Lower extremity biomechanical parameters during gait are of interest in degenerative pathologies, such as knee osteoarthritis. However, few investigations have looked at the effect of walking speed on knee biomechanics (e.g., moments). METHODS: 10 healthy volunteers (25.6 ± 5.0 years, 1.68 ± 0.11 m, 70.3 ± 18.0 kg) completed 3 trials each of walking at 4 different speeds [preferred (PS), fast (FS), slow (SS), & very slow (VSS)]. The range for each speed was determined by measuring a percentage of the participants PS: FS = (120 ± 5%), SS = (80 ± 5%), and VSS = (50 ± 5%). Speed was determined using timing gates (Power Systems Brower) placed 2.4 meters apart. Data was collected using a motion capture system (VICON, 200Hz) while participants walked across a ~6-meter walkway; 4 in-line force plates (Bertec, 1000Hz) captured ground reaction force. Sagittal and frontal plane kinematics and kinetics at the knee were calculated for the 4 speeds using Visual 3D. Differences between the 4 speeds were analyzed using a repeated-measures GLM with pairwise comparisons (p<0.05). RESULTS: Average speed for the 4 conditions were: PS = 1.06 ± .17 m/s, FS = 1.29 ± .21 m/s, SS = .90 ± .16 m/s, and VSS = .73 ± .11 m/s. There was a significant main effect for speed (F2, 8 = 28.7, p = 0.034). Pairwise comparisons indicated a statistically significant difference in knee flexor moment for PS versus FS (PS = .181 ± .019, FS = .079 ± .015, p < .05) as well as in knee internal adductor moment for FS versus PS, SS, and VSS (FS = .026 ± .083, PS = -.437 ± .068, SS = -.579 ± .170, VSS = -.363 ± .112, p < .05). Knee flexor moments were smaller for FS versus PS, while FS was also smaller than PS, SS, and VSS for the knee adductor moment. CONCLUSION: Our findings agree with previous research that identified differences in knee flexor and adductor moments at different gait speeds. For pathological populations it is important to understand the effect of gait speed on knee adductor moment since it is a surrogate measure for joint loading. However, our sample size was small; therefore, the effect of gait speed on knee flexor and adductor moments should be further investigated. Future studies will seek to understand the relative contribution of the quadriceps’s muscles at different speeds and its impact on knee joint loads.