Comparison of difficulty in stair ascent and descent after total knee replacement.

[Purpose] Although many studies have shown that patients have difficulty in climbing or descending stairs after undergoing total knee replacement, no study so far has compared the difficulty of stair ascent and descent based on objective indicators. This study compared stair ascending and descending processes based on three indicators and clarified which was more difficult. [Participants and Methods] We defined 1) movement method, 2) the necessity for handrail use, and 3) speed as objective indicators. Seventy-eight patients who underwent total knee replacement participated in this study. Three months after the surgery, we examined 1) whether the patients could ascend or descend in a step-over-step or step-by-step manner, 2) whether the patients required handrail support, and measured 3) the time required to ascend and descend for four steps. [Results] The step-by-step movement and handrail requirement rates associated with stair descent were higher than the corresponding rates associated with stair ascent. In addition, the time required for stair descent was greater than that required for ascent. [Conclusion] We found that stair descent was more challenging than stair ascent in terms of all three objective indices: movement method, handrail use, and speed. The results indicate that rehabilitation after total knee replacement should focus more on stair descent than on stair ascent.

Examination of the Impact of Strength and Velocity of the Knee and Ankle on Gait Speed in Community-Dwelling Older Adults.

The muscle strength of the knee extension and plantarflexion plays a crucial role in determining gait speed. Recent studies have shown that no-load angular velocity of the lower limb joints is essential for determining gait speed. However, no reports have compared the extent to which lower limb functions, such as knee extension strength, knee extension velocity, plantarflexion strength, and plantarflexion velocity, impact gait speed in a single study. Therefore, this study aimed to examine the relative importance of maximum strength and no-load angular velocity on gait speed. Overall, 164 community-dwelling older adults (72.9 ± 5.0 years) participated in this study. We measured the gait speed and lower limb function (the strength and velocity of knee extension and plantarflexion). Strength was measured with a hand-held dynamometer, and velocity with a gyroscope. A multiple regression analysis was performed with gait speed as the dependent variable and age, sex, and lower-limb function as independent variables. Plantarflexion velocity (ß = 0.25) and plantarflexion strength (ß = 0.21) were noted to be significant predictors of gait speed. These findings indicate that no-load plantarflexion velocity is more important than the strength of plantarflexion and knee extensions as a determinant of gait speed, suggesting that improvement in plantarflexion velocity may increase gait speed.