Reliability and Validity of the Sit-to-Stand as a Muscular Power Measure in Older Adults

Relationship between Asymmetries and Functional Autonomy in Older Chilean Adults

The objectives of this study were: (a) to determine asymmetries, both lower limb (LL) and upper limb (UL), in Chilean older adults, and (b) to relate asymmetries to FA in both LL and UL. Forty-one older adults voluntarily participated in this study (mean ± standard deviation [SD]: age 72.0 ± 8.0 years, LL asymmetries 13.78 ± 14.87%, UL asymmetries 10.70 ± 8.85%, FA 40.35 ± 16.26 points). The variables were: (1) asymmetries of LL and UL, assessed through a force platform and handgrip, respectively; (2) FA, assessed through the Latin American Group for Maturity (GDLAM) and the GDLAM index of autonomy (GI) protocol. The relationship between the variables was performed through Spearman's correlation. The analysis showed that 39% of the participants presented asymmetries above 15% in the LL. Likewise, this 39% of older adults presented a lower FA than their peers with asymmetries below 15% in the LL (≤15%: 35.64 ± 12.26 points vs. >15%: 47.69 ± 19.23 points, p = 0.003). The analysis showed a small correlation between LL and GI asymmetries (r = 0.27, p = 0.07) and a small but negative correlation between UL and GI (r = -0.21). The mean values of asymmetries of both LL and UL are within 'normal' parameters. However, several older adults were identified as being at risk. In parallel, older adults who presented a higher level of asymmetries in LL showed a lower level of FA.

Effects of 12 weeks of aerobic exercise combined with resistance training on neurocognitive performance in obese women

Background/Objectives

To the best of our knowledge, there have been no previous studies conducted on the long-term effects of an exercise intervention on deficits in inhibitory control in obese individuals. The aim of this study was thus to examine the effect of 12 weeks of a combination of aerobic and resistance exercise on behavioral and cognitive electrophysiological performance involving cognitive interference inhibition in obese individuals.

Methods

Thirty-two qualified healthy obese women were randomly divided into either an exercise group (EG, age: 34.76 ± 5.52 years old; BMI: 29.35 ± 3.52 kg/m²) or a control group (CG, age: 33.84 ± 7.05 years old; BMI: 29.61 ± 4.31 kg/m²). All participants performed the Stroop task, with electrophysiological signals being collected simultaneously before and after a 12-week intervention. The estimated V̇O₂max, muscular strength, and body fat percentage (measured with dual-energy X-ray absorptiometry) were also assessed within one week before and after the intervention. Participants in the EG group engaged in 30 min of moderate-intensity aerobic exercise combined with resistance exercise, 5 sessions per week for 12 weeks, while the participants in the CG group maintained their regular lifestyle without engaging in any type of exercise.

Results

The results revealed that although a 12-week exercise intervention did not enhance the behavioral indices [e.g., accuracy rates (ARs) and reaction times (RTs)] in the EG group, significantly shorter N2 and P3 latencies and greater P2 and P3 amplitudes were observed. Furthermore, the fat percentage distribution (e.g. total body fat %, trunk fat %, and leg fat %) and level of physical fitness (e.g. estimated V̇O₂max and muscular strength) in the EG group were significantly improved. The changes prior to and after the intervention in the P3 amplitude and trunk fat percentage were significantly negatively correlated in the EG group (r = −0.521, p = 0.039).

Conclusions

These findings suggested that 12 weeks of aerobic exercise combined with resistance exercise in obese women affects cognitive function broadly, but not specifically in terms of inhibitory control. The percentage of decreased trunk fat may play a potential facilitating role in inhibition processing in obesity.

Validity and reliability of handgrip dynamometry in older adults: A comparison of two widely used dynamometers

Background

Among older adults, decreased handgrip strength is associated with greater risk of frailty, and loss of physical function, mobility, lean mass, and overall muscular strength and power. Frailty is also associated with sarcopenia, for which handgrip strength measurement has been recommended for diagnostic purposes. Specific cutoff points for diagnosis have been identified, but use of different devices may affect measurement. Therefore to assess validity and reliability, we compared the two most frequently used devices, the Jamar hydraulic and Smedley spring handgrip dynamometers.

Methods

Sixty-seven older (76.2 ± 0.9 years) men (n = 34) and women (n = 33) completed two trials of handgrip strength measurement on sequential days (T1, T2) using both devices in random order. Intraclass correlations were used to assess test-retest reliability, and Bland-Altman analysis was used to assess validity as the level of agreement between devices.

Results

There were significant (p < 0.001) relationships between devices at T1 (r = 0.94) and T2 (r = 0.94) and strong (p < 0.001) intraclass correlations were observed for both devices (Jamar = 0.98; Smedley = 0.96), indicating excellent reliability. However, there were significant differences between devices. Strength measured with Jamar was greater than Smedley at both T1 (27.4 ± 1.4 vs. 23.4 ± 1.1 kg, p < 0.001) and T2 (25.3 ± 1.4 vs. 21.8 ± 1.2 kg, p < 0.001). Bland-Altman analysis confirmed these differences. Subgroup analysis to evaluate the effect of gender and age indicated that in women and old-old (>75 years) participants, differences between devices were closer to zero for both measurements compared to men and young-old (65–75 years) participants.

Conclusions

Our results demonstrate that despite excellent reliability, there is poor agreement between devices, indicating a lack of validity. For use as a diagnostic tool, standardization and device-specific cutoff points for handgrip dynamometry are needed.

Sit-to-Stand Power Across the Lifespan: A Cross-Sectional Analysis

Lower-body power measured by a linear position transducer during the sit-to-stand (STS) movement declines with age and may be a predictor of physical disability in older adults. The purpose of this study was to establish normative data for STS power across the lifespan and to determine if differences exist between age cohorts, sexes, and age cohort-sex subgroups. Adults (N = 557) aged 18-89 were divided into five age cohorts and performed the STS connected to a linear position transducer, which calculated power and velocity during the movement. Significantly lower (p < .01) velocity was observed in a younger age cohort in females than males, whereas males saw a significant average power decrement (p < .01) in a younger age cohort than females. STS power norms give clinicians a metric predicting physical disability and may be of particular interest to males as their power production begins to decline at an earlier age.

Test-Retest Reliability of Functional Electromechanical Dynamometer on Five Sit-to-Stand Measures in Healthy Young Adults

Background: The purpose of this study was to determine the reliability for the strength and movement velocity of the concentric phase from the five Sit-to-Stand (5STS), using three incremental loads measured by a functional electromechanical dynamometer (FEMD) in healthy young adults. Methods: The average and peak strength and velocity values of sixteen healthy adults (mean ± standard deviation (SD): age = 22.81 ± 2.13 years) were recorded at 5, 10 and 15 kg. To evaluate the reliability of FEMD, the intraclass correlation coefficient (ICC), standard error of measurement (SEM) and coefficient of variation (CV) were obtained. Results: Reliability was high for the 10 kg (CV range: 3.70–4.18%, ICC range: 0.95–0.98) and 15 kg conditions (CV range: 1.64–3.02%, ICC: 0.99) at average and peak strength, and reliability was high for the 5 kg (CV range: 1.71–2.84%, ICC range: 0.96–0.99), 10 kg (CV range: 0.74–1.84%, ICC range: 0.99–1.00) and 15 kg conditions (CV range: 0.79–3.11%, ICC range: 0.99–1.00) at average and peak velocity. Conclusions: The findings of this study demonstrate that FEMD is a reliable instrument to measure the average and peak strength and velocity values during the five STS in healthy young adults.

Validity, reliability, and measurement error of a sit-to-stand power test in older adults: A pre-registered study

OBJECTIVES

Lower body power declines with age and is associated with decreased physical function in older adults. However, the majority of the tools available to measure power are expensive and require considerable space and expertise to operate. The purpose of this study was to assess the validity, reliability, and measurement error of a sit-to-stand power test (STSp) to assess lower body power.

METHODS

51 community-dwelling adults, 65 years or older, completed a power test using a pneumatic leg press (LP), the Short Physical Performance Battery (SPPB) that includes a test of balance, usual walking speed, and chair stand tests; Timed Up and Go (TUG) test at both usual and fast paces, and Patient-Reported Outcome Measures (PROMs). A two-week test-retest assessed the reliability in 36 participants. The study hypotheses and analysis were pre-registered prior to data collection and statistical analyses were blinded.

RESULTS

The mean age was 71.3 years, with 63% females, and an average SPPB score of 10.6 (median = 12). STSp peak power was strongly correlated with LP (r = 0.90, 95% CI (0.82, 0.94). As hypothesized, the STSp peak power showed similar or higher correlations with physical function tests relative to LP peak power: SPPB (0.41 vs. 0.29), chair stand test (-0.44 vs. -0.35), TUG test at usual pace (-0.37 vs. -0.29) and fast pace (-0.41 vs. -0.34) and balance (0.33 vs. 0.22), but not for mobility (0.34 vs. 0.38) and function (0.41 vs. 0.48) questionnaire. For discriminant validity, as hypothesized, males showed higher STSp peak power compared to females (Δ = 492 W, p < .001, Cohen's d = 2.0). Test-retest assessment yielded an intraclass correlation coefficient of 0.96 and a standard error of measurement of 70.4 W. No adverse events were reported or observed for both tests.

CONCLUSION

The STSp showed adequate validity and reliability in measuring lower body power in community-dwelling older adults. The test is quick, relatively inexpensive, safe, and portable and thus should be considered for use in aging research.