Sofie Martien

Is knee extension strength a better predictor of functional performance than handgrip strength among older adults in three different settings

BACKGROUND The first purpose was to examine whether knee extension strength is a better predictor of functional performance than handgrip strength among older adults (≥60 years). The second purpose was to identify functionally relevant cut-off values for muscle strength. METHODS 770 community-dwelling older adults, 104 older adults living in assisted living facilities and 73 nursing home residents were included. Static strength, expressed in kg/kg body weight (BW), was measured using two field tests: handgrip (GRIP/BW) and knee extension (KNEE/BW) test. Functional performance was assessed with 6-Minute Walk Distance (6MWD, N=947) and modified Physical Performance Test (mPPT, N=152). RESULTS Both GRIP/BW and KNEE/BW were positively correlated with functional performance in all settings (p<0.05). In the community and nursing homes, both strength variables equally contributed to functional performance. In assisted living facilities, KNEE/BW (R(2)6MWD=0.39 and R2mPPT=0.35) was clearly a better predictor of functional performance than GRIP/BW (R(2)6MWD=0.15 and R2mPPT=0.12). GRIP/BW had no added value to KNEE/BW in order to explain the variance in functional performance. Functionally relevant cut-off values for static strength, for men and women respectively, were set at 0.40 and 0.31 for KNEE/BW and at 0.43 and 0.31 for GRIP/BW. CONCLUSIONS Handgrip and knee extension strength are both important predictors of functional performance in older adults. In assisted living facilities only, knee extension strength was clearly more predictive than handgrip strength. Both cut-off values appear to be highly sensitive to screen for functionally relevant muscle weakness in older adults.

Long-term effectiveness and mediators of a need-supportive physical activity coaching among Flemish sedentary employees

This study examined the long-term and mediation effects of a need-supportive coaching programme on physical activity. Sedentary employees (n = 92) of the university of Leuven received 4 months of physical activity coaching, based on the self-determination theory, by coaches with a bachelors degree in kinesiology who are specializing in health-related physical activity (n = 30). The programme consisted of a limited number of individual contact moments (i.e. an intake session, three follow-up contacts and an out-take session), either face-to-face, by phone or by e-mail. Self-reported physical activity, social support, self-efficacy and autonomous motivation were assessed in the coaching group (n = 92) and a control group (n = 34) at three moments: before the intervention (i.e. pre-test), after the intervention (i.e. post-test) and 1 year after pre-test measurements (i.e. follow-up test). Results revealed significant 3 (time) × 2 (groups) interaction effects on strenuous and total physical activity. Moreover, whereas the control group remained stable from pre- to post-test, the coaching group increased significantly in moderate, strenuous and total physical activity. Additionally, the coaching group increased significantly in mild, moderate, strenuous and total physical activity from pre- to follow-up tests, whereas the control group did not change. Bootstrapping analyses indicated that self-efficacy and autonomous motivation significantly mediated the intervention effect on physical activity from pre- to post-test, while social support significantly mediated the long-term effect. This study provides evidence for the long-term effectiveness of a need-supportive physical activity programme that might be efficient at the community level.

Energy Expenditure in Institutionalized Older Adults: Validation of Sensewear Mini

PURPOSE Objective methods to quantify physical activity (PA) and predict energy expenditure (EE) are needed in the old and old-old. The aim of the present study was to evaluate the validity of EE estimates by the SenseWear Mini (SWMini) compared with indirect calorimetry during daily life activities in institutionalized older adults. METHODS Sixty nursing home residents (mean age = 85.5 ± 5.5 yr) wore the SWMini during rest (sitting quietly) and three activity tasks (walking, sitting/rising/walking, and moving objects). SWMini data were processed using software version 7.0. The criterion EE (kcal·min⁻¹) was estimated by a portable gas analyzer, Oxycon Mobile (OM). RESULTS The analyses revealed high correlations (rsitting = 0.68, ractivity tasks = 0.88) between EE estimated by OM and SWMini. EE increased between sitting periods and activity tasks for EE estimated by OM (mean difference = 61.5% ± 8.9%), as well as for EE estimated by SWMini (mean difference = 58.2% ± 7.4%) (P < 0.001). However, SWMini significantly underestimated EE, with an overall absolute percent error of 14.1% ± 7.9%. The largest absolute percent differences were observed during sitting periods compared with activity tasks (P < 0.05). Older age significantly reduced accuracy, explaining 12% of the variance in total percent error (β = 0.42, t = 2.84, P < 0.05). CONCLUSIONS The high percent error scores indicate that the SWMini is of limited value for quantifying EE in the old and old-old. The accuracy could be improved by developing accurate age- and activity-specific algorithms. On the other hand, the SWMini can be used as a suitable device for researchers interested in specific levels and patterns of PA and sedentary behavior.

Counting Steps in Institutionalized Older Adults During Daily Life Activities: The Validation of Two Motion Sensors.

The primary purpose of this study was to assess the validity of two motion sensors in measuring steps in institutionalized older adults during daily life activities. Sixty-eight nursing home residents (85.8 ± 5.6 years) were equipped with a hip-worn and ankle-worn piezoelectric pedometer (New Lifestyles 2000) and with an arm-mounted multisensor (SenseWear Mini). An investigator with a hand counter tallied the actual steps. The results revealed that the multisensor and hip- and ankle-worn pedometer significantly underestimated step counts (89.6 ± 17.2%, 72.9 ± 25.8%, and 20.8 ± 24.6%, respectively). Walking speed accounted for 41.6% of the variance in percent error of the ankle-worn pedometer. The threshold value for accurate step counting was set at 2.35 km/hr, providing percent error scores within ± 5%. The ankle-worn piezoelectric pedometer can be useful for accurate quantification of walking steps in the old and old-old (≥ 85 years) walking faster than 2.35 km/hr.

Ergometer-cycling with strict versus minimal contact supervision among the oldest adults: A cluster-randomised controlled trial

OBJECTIVE To evaluate the feasibility and short- and long-term effects of two 10-wk structured ergometer-cycling programs among elderly in assisted-living residences. DESIGN, SETTING, AND PARTICIPANTS Eight assisted-living residences (N=95; age=81.2±5.9years) were randomly assigned to one of three conditions: 1) ergometer-cycling with strict coach-supervision (STRICT, N=3; n=35); 2) ergometer-cycling with autonomy-supportive minimal contact coach-supervision (AUT; N=3; n=36); or 3) control condition (CON; N=2, n=24). INTERVENTION Three-weekly progressive ergometer-cycling sessions for 10 weeks. MAIN OUTCOME MEASURES Feasibility, physical activity (PA), muscular strength, functional performance and quality of life (baseline, post-intervention (10weeks) and 6-month follow-up). RESULTS 83 participants were analyzed post-intervention, 75 at follow-up. Adherence was higher in STRICT than AUT during the intervention (p=0.001), but not during follow-up. Compared with CON, both programs showed positive short- and long-term effects on moderate-intensity PA (p=0.034). With regard to strength, functional performance and well-being, no time-by-group interaction effects were found. When comparing high-adherers (adherence≥80%) to low-adherers, a greater increase in functional performance and in well-being and a trend towards a lower decrease in strength were found in the short-term (p=0.047, p<0.001 and p=0.054, respectively). CONCLUSION Both interventions were feasible and equally effective to increase long-term engagement in PA, irrespective of the type of supervision. When adherence is high, positive effects on strength, performance and well-being can be expected.