Abstract
[Purpose] In order to establish a useful rehabilitation program for knee osteoarthritis (OA) patients, we tried to measure calf muscle oxygenation at various walking speeds. [Methods] The subjects were 7 older females with knee OA (OA group) and 7 older females who were not suffering from OA (non-OA group). All subjects performed treadmill walking at three different speeds for 2 minutes each with a rest period in between. The walking speeds were: 75% free gait speed (75%FGS), free gait speed (100%FGS), and 125% free gait speed (125%FGS). We measured muscle oxygenation {blood volume (BV) and oxygenated hemoglobin (oxy-Hb)} at the medial head of the gastrocnemius muscle (GM) and the tibialis anterior muscle (TA) using near-infrared spectroscopy (NIRS). The differences of BV and oxy-Hb (Δ) were calculated from the mean value ten seconds before the start of walking and the mean value ten seconds after the end of walking for each condition. [Results] In the OA group both BV and oxy-Hb of GM and TA showed no significant differences among the conditions. In the non-OA group, however, the oxy-Hb of TA showed significant differences between the 75%FGS and 125%FGS conditions. [Conclusion] The different muscle oxygen patterns of the OA and non-OA groups might be explained by differences in the calf muscle pumping action during gait.
