Deficits Forces the Production of Grip Down Syndrome

Abstract

Summary Down syndrome (DS) and control individuals were examined as to their ability to adapt grip forces to changes in the properties of lifted objects. The DS group generated substantially greater grip forces than the controls in all tests and failed to adapt normally to changes in the frictional properties of the objects. Their greater grip forces were not due to greater slipperiness of the skin of their fingers. These results are consistent with other findings of subtle deficits in DS individuals' use of somatosensory information for controlling movement and posture. RÉSUMÉ Déficit dam I'effet d'agrippement chez le mongolien Des mongoliens (DS) et des contrbles ont été examinés pour leur capacitéà adapter des forces d'agrippement aux modification de propriété des objets soulevés. Le groupe DS générait des forces d'agrippement significativement plus élevées que les contrôles pour toutes les épreuves et échouaient à une adaptation normale aux modifications de propriétés de frottement des objets. Leur plus grande force d'agrippement n'était pas dûe au caractère plus glissant de leur doigts. Ces résultats coíncident avec d'autres données de déficits minimes dans I'utilisation par les mongoliens des informations sensorielles somatiques pour contrôler le mouvement et la posture. ZUSAMMENFASSUNG Störung der Greiffnktion bei Kindern mit Down Syndrom Kinder mit Down Syndrom (DS) und Kontrollkinder wurden hinsichtlich ihrer Fähigkeit untersucht, die Kraft beim Zugreifen der Lageveränderung von Gegenständen anzupassen. Die DS Gruppe hat bei allen Tests deutlich starkere Greifkräfte entwickelt als die Kontrollgruppe und konnte nicht normal auf Lageveränderungen von Gegenständen reagieren. Die stärkere Kraft des Zugreifens war nicht durch größere Schlüpfrigkeit der Haut ihrer Fingern bedingt. Die Ergebnisse stimmen mit anderen Befunden subtiler Störgungen bei der Verarbeitung somato‐sensorischer Information zur Bewegungs‐ und Haltungskontrolle bei DS Kindern überein. RESUMEN DCéficits en la produccion de fuerzas de prensión en individuos con sindrome de Down Se examinaron individuos con sindrome de Down (SD) y controles acerca de su habilidad para adaptar la fuerza de prensión a las propiedades de los objectos levantados. El grupo con SD producían de forma substancial unas mayores fuerzas de prensión que los controles en todas las pruebas y fallaron en la adaptación normal a los cambios de las propiedades de fricción de los objectos. Sus mayores fuerzas de prensión no se debian a un mayor deslizamiento de la piel de sus dedos. Estos resultados estan de acuerdo con otros hallazgos de deficits sutiles en individuos con SD en al uso de la informacion somárica para el control del movimiento y la postura.

Motor Behavior in Down Syndrome: Atypical Sensoriomotor Control

“…Previous studies showed that postural sway in subjects with somatosensory loss was significantly larger than normal on a firm surface but not on the sway-referenced surfaced, suggesting that sway-referencing disrupts somatosensory information for postural control already disrupted by neuropathy (Horak et al 2002). Our findings support the hypothesis of somatosensory deficits defended by such authors as Cole, Abbs & Turner (1988) showing that individuals with DS failed to modulate the grip force when were asked to lift one object with different surfaces and Brandt & Rosen (1995) showing low amplitudes for sensory nerve action potential following stimulation of the thumbs suggesting impaired peripherical somatosensory functions. Other possible explanation is a delay in central processing the afferent and efferent information at the cerebellum level because the cerebellum weight has been reported to be lower (Bellugi et al, 1990).…”

Time and frequency analysis of the static balance in young adults with Down syndrome

“…Compared to unaffected subjects, DS patients show lower levels of strength [12]; this is probably partly due to the action of factors such as number and type of muscle fibers, because the percentage of fast fibers in DS individuals is smaller than in people without disabilities [13]. DS patients are also less able than normal individuals to adapt their motor action to the circumstances and to generate greater strength when necessary [14]. These characteristics affect their general mobility and increase the difficulty they experience in performing coordinated movements and maintaining equilibrium [4,15].…”

Complexity of force output during static exercise in individuals with Down syndrome

“…With fewer functioning motor units active during force generation, each motor unit will have a higher firing rate and thus a proportionally greater impact on overall force output (23,64). Persons with DS typically exhibits 30 -40% lower levels of strength compared with their peers with mental retardation and Ͻ50% of the expected strength levels of their nondisabled peers (4,10,12,24,25,39). These low levels of muscle strength are present in childhood and persist into adulthood (27).…”