Relationship between Development of the Body-Righting Reaction and Manual Midline Crossing Behavior in the Learning Disabled

Abstract

The study was designed to consider the possible relationship between the development and integration of the body-righting reaction and the development of manual midline crossing behavior in learning-disabled and normal children aged 6 to 8 years (23 subjects in each group). A combination of three movement patterns (rolling from supine to prone, transition from supine to standing, and equilibrium in sitting) was used to analyze the body-righting reaction. The Space Visualization Contralateral Use (SVCU) score derived from the Southern California Space Visualization Test was used to measure manual midline crossing behavior. Results of the study found that the learning-disabled subjects exhibited significantly reduced performance on both test measures, when compared to the normal controls. A correlation between scores on the two tests did not reach significance. The findings are described as they relate to sensory integration testing, and the need for further study of the body-righting reaction and manual midline crossing behavior.

Midline-crossing Inhibition: An Indicator of Developmental Delay

“…Subje cts of norm al intelligence and considered developm entally norm al did not m anifest MCI. According to norm al developm ental patterns, by age 9 crosslateral integration should have been established (Cermak et al, 1980;Schofield, 1976;Stilwell, 1981) which was evident with these data. The absence of MCI with this non-e quivalent control group (Cambell & Stanley, 1963) helps to validate the developm entally delayed concept as applied to the group with mental retardation.…”

“…Cross-lateral integration is a developm ent milestone which is attained by age 8 or 9 (Cermak, Quintero, & Cohen, 1980;Schofield, 1976;Stilwell, 1981). Before this milestone is attained, individuals manifest a reluctance or hesitancy to execute motor tasks across the m idline of the body.…”

“…Benton (1955) reported that young individuals aged 11 to 22 years with brain injury m anifested midline-crossing problem s. Children with neurological-processing problems, identified as learning disabled, exhib ited MCI (Cerm ak & Ayres, 1984;Stilwell, 1981). Preadolescents and adolescents with m ild mental retardation had not attained the cross-lateral integration milestone and were found to have M CI.…”

“…Head' s protocol, usually referred as the Eye, Hand and Ear Test (Maloney, Ball, & Edga r, 1970), has been used to evaluate the absence of cross-lateral integration or M CI. M ore recently two tests developed by AyresÐ the Southe rn California Perceptual M otor Test (Ayres, 1972) and the Southern California Space Visualisation Test (Ayres, 1976)Ð have been used to m easure m idline-crossing behaviour (Stilwell, 1981). All these tests have a spatial component; subjects are asked to touch, reach, or grasp objects located on the ipsilateral or contralateral side of the individual.…”

Relationship between Manual Midline Crossing and Hand Preference

“…Disorders in manual midline crossing have been repeatedly observed in the school-aged learning-disabled population (Ayres, 1972;Kephart, 1960;Stilwell, 1981). Such disorders have been characterized by decreased frequency, as compared to the normative population, of contralateral band use, hand movements that cross the body midline and include approach or manipulation of objects in contralateral space (for example, using the right hand to grasp a toy on the left side of the body).…”