Force control is greater in the upper compared with the lower extremity.
The authors investigated whether force control is similar between the upper and lower limbs and between contractions that involve 1 or 2 joints. Six volunteers (27.5 +/- 11.2 years of age) attempted to produce consistent discrete rapid force responses of 30, 60, and 90 N by using 6 different body postures, 3 with the upper and 3 with the lower limb. One of the postures for each limb involved 2 joints. The standard deviation of peak force and impulse (aggregate of the force-time curve) was significantly greater ( approximately 25%) for the lower limb than for the upper limb (p <.01). Contractions that involved 1 or 2 joints within a limb had similar variability. Therefore, the upper limb might have better control of force than the lower limb because of its extensive use in fine motor tasks in daily activities.
Christou
Evangelos A
EA
Department of Integrative Physiology, University of Colorado at Boulder, Boulder, CO 80309-0354, USA. echristo@colorado.edu
Zelent
Mark
M
Carlton
Les G
LG
D000293:Adolescent; D000328:Adult; D004551:Elbow Joint / Q000502:physiology*; D005260:Female; D006621:Hip Joint / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D007699:Kinesthesis / Q000502:physiology*; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D005082:Physical Exertion / Q000502:physiology; D011187:Posture / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D012785:Shoulder Joint / Q000502:physiology*