This study aimed to continue our characterization of finger strength and multi-finger interactions across the lifespan to include those in their 60s and older. Building on our previous study of children, we examined young and elderly adults during isometric finger flexion and extension tasks. Sixteen young and 16 elderly, gender-matched participants produced maximum force using either a single ...

Finger-pressing forces are produced by activation of the intrinsic hand muscles, which are finger specific, and the extrinsic muscles that connect to multiple fingers. We tested a hypothesis of greater weakening of intrinsic hand muscles with age and quantified associated indexes of finger interaction such as enslaving (force production by unintended fingers) and force deficit (loss of finger f...

We studied the effects of fatigue of the index finger on indices of force variability in discrete and rhythmic accurate force production tasks performed by the index finger and by all four fingers pressing in parallel. An increase in the variance of the force produced by the fatigued index finger was expected. We hypothesized that the other fingers would also show increased variance of their fo...

In a majority of studies on grasp, only normal forces were measured and only when a zero torque was exerted on a hand-held object. This study concerns finger force vectors during the torque production tasks. Subjects (n=8) stabilized a handle with an attachment that allowed for change of external torque from -1.5 to 1.5 Nm. Forces and moments exerted by the digit tips on the object were recorde...

Carpal tunnel syndrome (CTS) refers to a class of injuries characterized by compression of the median nerve in the carpal tunnel. CTS injuries cause pain, weakness, and numbness in the hands and are common among video gamers and workers that maintain their wrists in ergonomically unfavorable positions. Current CTS qualification methods are well documented, whereas the condition of the hand musc...

We investigated finger strength and the ability to control digit force/torque production in children with developmental coordination disorder (DCD) using manipulative tasks with different kinetic redundancies (KNR). Age-related changes in finger strength and finger force/torque control in typically developing (TD) children were also examined to provide a developmental landscape that allows a co...

The objective of the study is to examine the effects of age and gender on finger coordination. Twelve young (24 +/- 8 yr; 6 men and 6 women) and 12 elderly (75 +/- 5 yr; 6 men and 6 women) subjects performed single-finger maximal contraction [maximal voluntary contraction (MVC)], four-finger MVC, and four-finger ramp force production tasks by pressing on individual force transducers. A drop in ...

When one finger changes its force, other fingers of the hand can show unintended force changes in the same direction (enslaving) and in the opposite direction (error compensation). We tested a hypothesis that externally imposed changes in finger force predominantly lead to error compensation effects in other fingers thus stabilizing the total force. A novel device, the "inverse piano", was used...