The Relationship Among Body Mass Index, Balance, and Motor Skill Performance

Purpose: To assess motor development among children from a low SES group in the community (Lubbock), and investigate the impact of body weight (BMI) is on motor and balance skills.

Methods: Children (N=41; 5-10.83 years old) attending two motor programs (a. Parkway, Pk: K classes from Parkway School, 5-6 years old), and, b. Fun and Fit (FF: 9-11 year olds at-risk for weight issues and recruited from Lubbock ISD) at Texas Tech University were assessed. Body Mass Index (BMI) was determined through the CDC provided algorithm. The Test of Gross Motor Development (TGMD-2) assessed their motor skills with the gross motor quotient (GMQ) used as index of motor performance. The Sensory Organization Test (SOT, NeurocomŽ) assessed balance: SOT composite scores were used as benchmark. Participants were grouped according to their BMI yielding the following sub-classifications: healthy-weight (HW), at-risk for being overweight (AtR), overweight (OvrW) and obese (OB) subjects.

Analysis/Results: A stark but expected contrast was evident among programs (Pk vs FF) in GMQ scores: younger children (Pk) outscored the FF group (older with weight issues). However, older FF group outperformed the younger Pk group in mean SOT scores. Based on BMI subgroups, significant group differences were found in GMQ scores with HW children (M =91) outperforming the two highest BMI groups: OvrW (M = 78) and OB (M = 60), while non-significant differences were found based on SOT scores. Correlation analyses of GMQ and BMI scores were consistent with moderate to high negative correlation (r= -0.69), while correlation analyses between SOT and BMI was low (r=0.14).

Conclusions: With increasing age, GMQ scores should increase with mastery of motor skills, but not here. Older, heavier subjects (FF) were outperformed by younger HW (healthy weight) subjects (Pk). The correlations clearly showed BMI impacting GMQ. As BMI increased, GMQ decreased, showing a (moderate to high) negative relationship between these two variables. GMQ scores were highest in HW subjects and lowest in the overweight (OvrW) and obese (OB) subjects. When motor performance was broken down into subcomponents of locomotion and object manipulation, correlation levels were maintained, although the correlation was stronger between LOC and BMI. Weight affects locomotion more than object manipulation tasks. Yet the correlation of OBJ scores to BMI was comparable, indicating that with this particular group major risks for motor skill delay is evident even in tasks traditionally not affected by weight (e.g. catching, throwing, rolling etc.).