Berrigan F, Simoneau M, Tremblay A, Hue O, Teasdale N
Groupe de Recherche en Analyse du Mouvement et Ergonomie (GRAME), Québec, Canada.
Int J Obes (Lond). 2006 Dec;30(12):1750-7. doi: 10.1038/sj.ijo.0803342. Epub 2006 Apr 18.
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.
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.
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.
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.
肥胖会导致姿势稳定性下降。然而，肥胖对上肢运动控制的潜在负面影响尚未得到证实。本研究旨在探讨肥胖是否会施加额外的平衡控制限制，从而限制从直立站立姿势执行上肢目标导向运动的速度和准确性。
八名健康瘦人受试者（体重指数（BMI）在20.9至25.0kg/m²之间）和九名健康肥胖受试者（BMI在30.5至48.6kg/m²之间）从直立站立姿势指向他们前方的一个目标。任务是在听到听觉信号后尽可能快速、准确地瞄准目标。通过使用不同大小的目标（宽度为0.5、1.0、2.5和5.0厘米）来改变任务难度。测量手部运动时间（MT）和速度曲线以量化瞄准情况。分析压力中心和节段运动学以记录姿势稳定性。
在瞄准过程中，肥胖组向前的压力中心（CP）位移大于正常BMI组（分别为4.6厘米和1.9厘米）。对于肥胖组，目标尺寸减小与向后CP位移和CP峰值速度增加相关，而对于正常BMI组，在所有目标尺寸下向后CP位移和CP峰值速度大致相同。肥胖参与者通过向前移动全身来瞄准目标，而正常BMI受试者主要进行肘部伸展和肩部屈曲。对于两组，MT都随着目标尺寸减小而增加。与正常BMI组相比，肥胖组的这种影响更为明显。对于两个最小的目标，肥胖受试者的运动平均比正常BMI组慢115和145毫秒，这表明肥胖增加了平衡限制并限制了准确运动的速度。
肥胖由于其对平衡控制的影响，也对目标导向运动施加限制。从临床角度来看，在大量需要从直立站立姿势进行上肢运动的工作任务和日常活动中，肥胖个体可能比正常体重个体效率更低且受伤风险更高。
