Impaired balance is a significant risk factor for falls among older adults. The precise impact of lower-extremity muscles, including the proportion of muscle strength, on the performance of single-leg standing balance tests in older individuals is very interesting. The aim of this study is to examine the correlation between the knee extensor (KE), ankle plantar flexor (AP) muscle strength, and performance in single-leg standing balance tests in older females. Additionally, it aims to evaluate the combined proportion of KE and AP muscle strength in maintaining balance during single-leg standing. A total of 90 older females (mean age 67.83 ± 8.00 years) were recruited. All participants underwent maximum voluntary isometric contraction (MVIC) testing of the KE and AP muscles, as well as single-leg standing balance tests with eyes open (SSEO) and eyes closed (SSEC). To examine the influence of KE and AP muscle strength on balance performance, multiple regression analysis was conducted. Low correlations were found between SSEO and MVIC of KE and AP muscles, but moderate correlations were found with percentage of MVIC to body weight ratio (%MVIC/BW). The best model for SSEO included 0.99 times of the %MVIC/BW of AP and 0.66 times that of KE muscles as independent predictor variables (r = 0.682). In conclusion, AP muscle strength was found to have a greater impact on single-leg standing balance compared with KE muscle strength.

The senior population is at increased risk of falling due to a reduction in ankle muscle strength. Evaluating the strength of the ankle muscles in older adults is of paramount importance. The purpose of this study was to formulate an equation to estimate ankle muscle strength by utilizing the basic physical characteristics of the subject and the variables related to their ability to perform the standing heel-rise test (SHRT). One hundred and thirty-two healthy elderly participants (mean age 67.30 ± 7.60) completed the SHRT and provided demographic information. Ankle plantar flexor (PF) muscle strength was evaluated using a push–pull dynamometer. Multiple regression analysis was utilized to develop a prediction equation for ankle PF muscle strength. The study revealed that the ankle PF strength equation was derived from variables including the power index of the SHRT, gender, age, calf circumference, and single-leg standing balance test. The equation exhibited a strong correlation (r = 0.816) and had a predictive power of 65.3%. The equation is represented as follows: ankle PF strength = 24.31 − 0.20(A) + 8.14(G) + 0.49(CC) + 0.07(SSEO) + 0.20(BW/t-SHRT). The equation had an estimation error of 5.51 kg. The strength of ankle PFs in elderly individuals can be estimated by considering demographic variables, including gender, age, calf circumference, single-leg standing balance test, and the power index of the SHRT. These factors were identified as significant determinants of ankle PF strength in this population.

Objectives. This study aimed to evaluate and compare the functional capacity of young adults recovering from COVID-19 using the 6-Minute Walk Test (6MWT) and 2-Minute Step Test (2MST), focusing on cardiovascular parameters, and to examine correlations between these tests, demographic factors, and muscle strength. Materials and methods. A cross-sectional study was conducted with 34 young participants (mean age: 20.62 years, 88.24 % female), all experiencing mild post-COVID-19 symptoms. Muscle strength (grip and quadriceps strength) was assessed, and functional capacity was evaluated using the 6MWT and 2MST, with the test order randomized by drawing lots. Hemodynamic responses, fatigue, and dyspnea were measured before and after both tests. Paired t-tests were used to compare cardiovascular parameters and leg fatigue between the 6MWT and 2MST. Pearson’s correlation coefficient assessed relationships between both tests, demographics, and muscle strength. Results. The study revealed an increase in heart rate and leg fatigue after the 6MWT compared to the 2MST, whereas systolic blood pressure was elevated following the 2MST compared to the 6MWT. The 6MWT showed a significant positive correlation with the 2MST (r = 0.350, p = 0.043). Additionally, quadriceps strength was positively correlated with both the 6MWT (r = 0.372, p = 0.030) and the 2MST (r = 0.395, p = 0.021). Conclusions. The findings of this study indicate that both the 6MWT and 2MST are effective in assessing functional capacity in young individuals recovering from COVID-19, showing distinct physiological responses. Furthermore, quadriceps strength is correlated with both tests, highlighting the importance of muscle strength in recovery.

Background: Scapular correction has been demonstrated to improve pain, cervical range of motion (CROM), joint position error (JPE), and pressure pain threshold (PPT) in individuals with neck pain. However, whether active or passive scapular correction produces superior acute, short-term adaptations remains unknown. Objective: The study aimed to investigate the immediate and 30-min follow-up effects of active and passive scapular correction, compared to sham control, on pain, CROM, JPEs, and PPTs in people with neck pain and scapular dysfunction. Methods: In this double-blind randomized controlled trial, seventy-eight participants with neck pain and scapular dysfunction were randomly allocated to active, passive, or sham scapular correction. Each intervention consisted of 10 repetitions of 10 s: active self-correction in the active group, physiotherapist-performed passive correction in the passive group, or gentle touch in the sham group. Pain, CROM, JPEs, and PPTs were assessed at baseline, immediately post-intervention, and at 30-min follow-up. Results: Immediately post-intervention, both active and passive groups demonstrated reduced pain intensity and increased CROM and PPTs compared to the sham group (all p < 0.05). At 30-min follow-up, these improvements were maintained only in the active group (all p < 0.05). Reductions in cervical and shoulder JPEs were observed only in the active group immediately post-intervention (all p < 0.05). Conclusion: Both active and passive scapular correction effectively improved pain intensity, cervical mobility and pain sensitivity immediately after intervention. However, active scapular correction may provide greater benefits by maintaining these effects at 30-min post-intervention and immediately improving joint position sense.