Influence of obesity on accurate and rapid arm movement performed from a standing posture

Abstract

Introduction: Obesity yields a decreased postural stability. The potentially negative impact of obesity on the control of upper limb movements, however, has not been documented. This study sought to examine if obesity imposes an additional balance control constraint limiting the speed and accuracy with which an upper limb goal-directed movement performed from an upright standing position can be executed. Method: Eight healthy lean subjects (body mass index (BMI) between 20.9 and 25.0 kg/m 2 ) and nine healthy obese subjects (BMI between 30.5 and 48.6 kg/m 2 ) pointed to a target located in front of them from an upright standing posture. The task was to aim at the target as fast and as precisely as possible after an auditory signal. The difficulty of the task was varied by using different target sizes (0.5, 1.0, 2.5 and 5.0 cm width). Hand movement time (MT) and velocity profiles were measured to quantify the aiming. Centre of pressure and segmental kinematics were analysed to document postural stability. Results: When aiming, the forward centre of pressure (CP) displacement was greater for the obese group than for the normal BMI group (4.6 and 1.9 cm, respectively). For the obese group, a decrease in the target size was associated with an increase in backward CP displacement and CP peak speed whereas for the normal BMI group backward CP displacements and CP peak speed were about the same across all target sizes. Obese participants aimed at the target moving their whole body forward whereas the normal BMI subjects predominantly made an elbow extension and shoulder flexion. For both groups, MT increased with a decreasing target size. Compare to the normal BMI group, this effect was exacerbated for the obese group. For the two smallest targets, movements were on average 115 and 145 ms slower for the obese than for the normal BMI group suggesting that obesity added a balance constraint and limited the speed with which an accurate movement could be done. Summary: Obesity, because of its effects on the control of balance, also imposes constraints on goal-directed movements. From a clinical perspective, obese individuals might be less efficient and more at risk of injuries than normal weight individuals in a large number of work tasks and daily activities requiring upper limb movements performed from an upright standing position.

Body Mass Index and Serum γ‐glutamyltransferase Level as Risk Factors for Injuries Related to Professional Horse Racing: A Prospective Study

“…Additionally, physical movements by obese men may be less efficient leading to such individuals being at higher risk of injuries than those with normal weight in a large number of work tasks and daily activities 28) . Previous studies reported that weight loss improves balance control in obese subjects and the extent of the improvement was directly related to the amount of weight loss 29,30) .…”

Childhood obesity affects postural control and aiming performance during an upper limb movement

“…Many of these studies investigated the effect of obesity on gross motor skills such as walking backwards along balance beams of decreasing width, moving sideways on wooden boards, one-legged hopping over a foam obstacle, and two-legged jumping from side to side [12,13], or on fine motor skills such as a peg placing task [6]. However, the relationship between obesity and the execution of motor tasks challenging the movement control at different difficulty levels realized in different postural context have not been closely documented among children, although it has been in adults [1,2]. Obesity adds a balance control constraint, however, movement time would be longer when the aiming requires more precision in standing and seated position for children, explaining the results previously observed for a functional task [12,13].…”

“…Recent studies showed that obesity was linked with a reduced efficiency of mechanisms responsible for postural and movement control in standing position among adults [1][2][3][4]. For instance, reduced postural stability while standing leads to longer movement time and deceleration phase during a goal-directed movement in obese [2].…”

Excess body fat is associated with higher risk of vertebral deformities in older women but not in men: a cross-sectional study

“…There are also many other possible associations between fat mass and bone mass on the molecular and cell level, including adipocyte hormones, estrogens, leptin, IL-6 and insulin [16,17]. In addition to any effects relating to bone mass, obesity has been postulated to increase the risk of falling [18], as it has been shown to increase postural instability [19,20] and decrease accuracy when performing rapid movements [19].…”