No abstract

Older individuals have impaired balance control, particularly those that are frail and/or have sensory deprivations. Obese individuals show faster body sway during upright stance than normal weight individuals, suggesting that they also have difficulty controlling balance even if they do not have the same sensory issues as the older people. Therefore, the objective of this study was to examine if obesity is associated to a decreased balance control in older women. Postural sway of normal weight (n 015, age070.8±5.5 years; BMI022.2±1.9 kg/m 2 ), overweight (n 015, age 071.7 ± 4.3 years; BMI 027.3 ± 1.3 kg/m 2 ), and obese (n015, age071.1±4.3 years; BMI033.1±3.4 kg/m 2 ) women was measured with a force platform for normal quiet stance lasting for 30 s in opened and closed eyes conditions. The obese group oscillated at a faster speed than the normal weight group (vision 0.99 ± 0.29 cm/s vs. 0.70 ± 0.16 cm/s, p<0.01; no vision 1.43± 0.50 cm/s vs. 0.87±0.23 cm/s, p<0.01). The obese group exhibited greater range in both axes without vision compared to the normal weight group (p<0.05). When observing sway density parameters, the obese group also spent less time in stability zones (2 mm radius area in which the center of pressure is relatively stable), and the distance between these stability zones are greater than the normal weight group in both visual conditions (p< 0.01 and p<0.05, respectively). Obesity clearly affects postural control in older women. Our results suggest that obesity has a negative impact on the capacity of older woman to adequately use proprioceptive information for posture control. As postural instability or balance control deficits are identified as a risk factor for falling, our results also suggest that obesity in older women could be considered as another potential contributing factor for falling.

No abstract

Muscle recruitment is altered in patients with chronic LBP in the presence of muscle fatigue. Consequently, these patients exhibit changes in muscle recruitment pattern and intensity (lower levels of motor variability) during sustained isometric contraction that may be attributed to variation in the control of motor units within and between muscles. However, patients with LBP are able to increase their motor variability over time but with a lower increase compared to healthy participants.