Practice of a precision isometric grip‐force task by children with spastic cerebral palsy

Abstract

The ability to produce and sustain a criterion level of precision isometric grip force was studied in a group of 7‐ to 12‐year‐old children with cerebral palsy (CP) and in a control group. On‐line visual feedback of the forces produced relative to a stationary target was provided for each 5‐second trial. Subjects practised 48 trials on each of 3 consecutive days. Measures of accuracy and variability revealed significantly reduced accuracy and increased variability in isometric force production for the group with CP. Both groups demonstrated improvement with practice, with the significantly greater change in the control subjects. There was substantial variability in performance among subjects with CP. Gains associated with practice were sustained over a 5‐day retention interval for both groups. The requirement to control proximal segments of the upper extremity was not associated with increased error in grip‐force production of the group with CP.

Reliability of hand-held dynamometry and functional strength tests for the lower extremity in children with Cerebral Palsy

“…Both muscle strength tests are influenced by the motivation or co-operation of a patient. Moreover, children with CP show a large variability in the generation of muscle strength [41]. Cognitive impairment has been cited as a possible reason for large withinparticipant variability when testing isokinetic strength [35].…”

Quantitative assessment of motor abnormalities in untreated patients with major depressive disorder

“…For example, investigators have employed measures of force variability to quantify disease progression in Huntington’s disease (Reilmann et al, 2001). Studies in cerebral palsy and stroke have demonstrated that individuals with these illnesses cannot maintain the levels of precise force necessary to perform simple grip tasks, suggesting an important role for the motor cortex in the generation and maintenance of fine muscle force (Hermsdorfer and Mai, 1996; Valvano and Newell, 1998). Investigators have reported elevated levels of force variability in individuals with schizotypal personality disorder (Neumann and Walker, 1999) and schizophrenia (Caligiuri and Lohr, 1994), suggesting disturbances of inhibitory mechanisms regulating motor control.…”

Variation and Variability: Key Words in Human Motor Development

“…Second, impaired selection induces the need of ten-to hundredfold more active motor experience than typically needed to find the best strategy. 69,70 Consequentially, children with CP need considerably more practice than their peers without CP to learn a specific motor task.…”