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.

Age-related changes and sex differences in ankle plantarflexion velocity.

Ankle plantar flexors play a vital role in the mobility of older adults. The strength and velocity of plantarflexion are critical factors in determining walking speed. Despite reports on how age and sex affect plantarflexion strength, basic information regarding plantarflexion velocity is still lacking. This cross-sectional observational study investigated age-related changes and sex differences in plantarflexion velocity by comparing them with plantarflexion strength. A total of 550 healthy adults were classified into four age groups for each sex: Young (< 40 years old), Middle-aged (40-64 years old), Young-old (65-74 years old), and Older-old (≧ 75 years old). We measured plantarflexion velocity and strength in the long-sitting position using a gyroscope and a hand-held dynamometer, respectively. Two-way analysis of variance revealed no interaction between age and sex for either plantarflexion velocity or strength. Plantarflexion velocity exhibited a significant decline with aging, as did the plantarflexion strength. We found no significant sex differences in plantarflexion velocity in contrast to plantarflexion strength. The results indicated a significant decrease with age and no difference in plantarflexion velocity between males and females characteristic plantarflexion velocity. Understanding the characteristics of plantarflexion velocity could contribute to preventing a decline in mobility in older adults.

Maximum knee extension velocity without external load is a stronger determinant of gait function than quadriceps strength in the early postoperative period following total knee arthroplasty.

OBJECTIVE: Quadriceps weakness is considered the primary determinant of gait function after total knee arthroplasty (TKA). However, many patients have shown a gap in improvement trends between gait function and quadriceps strength in clinical situations. Factors other than quadriceps strength in the recovery of gait function after TKA may be essential factors. Because muscle power is a more influential determinant of gait function than muscle strength, the maximum knee extension velocity without external load may be a critical parameter of gait function in patients with TKA. This study aimed to identify the importance of knee extension velocity in determining the gait function early after TKA by comparing the quadriceps strength. METHODS: This prospective observational study was conducted in four acute care hospitals. Patients scheduled for unilateral TKA were recruited (n = 186; age, 75.9 ± 6.6 years; 43 males and 143 females). Knee extension velocity was defined as the angular velocity of knee extension without external load as quickly as possible in a seated position. Bilateral knee function (knee extension velocity and quadriceps strength), lateral knee function (pain and range of motion), and gait function (gait speed and Timed Up and Go test (TUG)) were evaluated before and at 2 and 3 weeks after TKA. RESULTS: Both bilateral knee extension velocities and bilateral quadriceps strengths were significantly correlated with gait function. The knee extension velocity on the operation side was the strongest predictor of gait function at all time points in multiple regression analysis. CONCLUSION: These findings identified knee extension velocity on the operation side to be a more influential determinant of gait function than impairments in quadriceps strength. Therefore, training that focuses on knee extension velocity may be recommended as part of the rehabilitation program in the early postoperative period following TKA. TRIAL REGISTRATION: UMIN Clinical Trials Registry (UMIN-CTR) UMIN000020036.

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.

Immediate Effects of Single-Session High-Velocity Training for Lateral Trunk Movement on Gait Function in Early Postoperative Patients after Total Hip Arthroplasty: A Nonrandomized Controlled Trial.

BACKGROUND: Total Hip Arthroplasty (THA) is an effective method for relieving pain and improving gait function. However, THA patients demonstrate slow gait speed at discharge. Rehabilitation programs after THA require the immediate improvement of gait speed early in the postoperative period. To examine the immediate effects of seated side tapping training (SSTT), which focuses on lateral trunk movement and movement velocity, on gait function in early postoperative THA patients, the methods were as follows: The SSTT group performed five repetitions of a task in which they moved their trunks laterally to alternately touch markers to their left and right side as quickly as possible 10 times in a seated position. One set of SSTT lasted approximately 3 min. The control group rested in a seated position for 10 min. RESULTS: Significant interactions were observed for gait speed, stride time, and stride time coefficient of variability. The SSTT group demonstrated significant pre-post-intervention improvement in gait speed, stride time, and coefficient of variability. CONCLUSIONS: SSTT improved both gait speed and gait stability and can be performed easily and safely. Therefore, single-session high-velocity trunk training may be an effective method to improve gait function immediately in early postoperative THA patients.