Strength is the most important determinant of mobility status among children with motor impairments. Obesity, a common problem among disabled children, is a second important factor negatively influencing mobility status in disabled children. this study focuses on strength and body fat as determinants of energy cost of ambulation and wheelchair locomotion in children with variable degrees of mobility impairment due to myelomeningocele (MM), spinal cord injury (SCI), cerebral palsy (CP), and Duchenne Muscular dystrophy (DMD). Specifically, the primary aims of the proposal will address two hypotheses: 1) excess body fat increases the energy cost of ambulation and wheelchair locomotion over and beyond the increased costs associated with lean tissue deficits and weakness, and 2) higher energy cost of locomotion is associated with reductions in daily total energy expenditure (TEE) and physical activity; reduced physical activity will be associated with increased adiposity. The study population consists of 375 male and female children ages 6 to 20: 90 MM, 45 SCI, 120 CP, 30 DMD, and 90 controls. Measurements include: 1) anthropometrics, 2) whole body and regional body composition by dual-energy x-ray absorptiometry (DXA), 3) quantitative isometric and isokinetic strength at the elbow and knee, 4) resting metabolic rate (RMR) by indirect calorimetry, 5) energy cost of ambulation and/or wheelchair locomotion (ml O2/Kg meter and Kcal/Kg meter) via a portable telemetric metabolic, measurement system, and 6) TEE and physical activity index (TEE/RMR ratio) by continuous three day heart rate (HR) monitoring. The energy cost of locomotion will be accessed at baseline and with added weight via a pelvic belt equivalent to a 10% increase in % body fat and a 20% increase in % body fat. We will determine the relative importance of weakness and decreased ratio of lean tissue to total body mass in producing increased energy cost of locomotion, reduced physical activity (as evidenced by the TEE:RMR ratio) and a risk of increased adiposity for disabled children. Objective measures of both energy economy of locomotion and physical activity are functionally relevant outcomes. Establishment of a relationship of both impaired strength and increased adiposity to increased energy cost, and hence, reduced physical activity, will provide a basis for varied interventions to improve functional mobility. Outcome studies assessing interventions directed at improving the energy efficiency of locomotion will need to also consider body composition changes over time if there are indeed significant incremental energy costs during locomotion associated with increased adiposity.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD035714-02
Application #
2674134
Study Section
Special Emphasis Panel (ZHD1-RRG-K (07))
Project Start
1997-08-01
Project End
2001-07-31
Budget Start
1998-08-01
Budget End
1999-07-31
Support Year
2
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of California Davis
Department
Physical Medicine & Rehab
Type
Schools of Medicine
DUNS #
094878337
City
Davis
State
CA
Country
United States
Zip Code
95618
Liusuwan, Rungsinee Amanda; Widman, Lana M; Abresch, Richard Ted et al. (2007) Body composition and resting energy expenditure in patients aged 11 to 21 years with spinal cord dysfunction compared to controls: comparisons and relationships among the groups. J Spinal Cord Med 30 Suppl 1:S105-11
Nelson, Mindy Dopler; Widman, Lana M; Abresch, Richard Ted et al. (2007) Metabolic syndrome in adolescents with spinal cord dysfunction. J Spinal Cord Med 30 Suppl 1:S127-39
Widman, Lana M; Abresch, Richard Ted; Styne, Dennis M et al. (2007) Aerobic fitness and upper extremity strength in patients aged 11 to 21 years with spinal cord dysfunction as compared to ideal weight and overweight controls. J Spinal Cord Med 30 Suppl 1:S88-96
McDonald, Craig M; Abresch-Meyer, Allison L; Nelson, Mindy Dopler et al. (2007) Body mass index and body composition measures by dual x-ray absorptiometry in patients aged 10 to 21 years with spinal cord injury. J Spinal Cord Med 30 Suppl 1:S97-104
Liusuwan, Rungsinee Amanda; Widman, Lana M; Abresch, Richard Ted et al. (2007) Behavioral intervention, exercise, and nutrition education to improve health and fitness (BENEfit) in adolescents with mobility impairment due to spinal cord dysfunction. J Spinal Cord Med 30 Suppl 1:S119-26
McDonald, Craig M; Widman, Lana M; Walsh, Denise D et al. (2005) Use of step activity monitoring for continuous physical activity assessment in boys with Duchenne muscular dystrophy. Arch Phys Med Rehabil 86:802-8
McDonald, Craig M; Carter, Gregory T; Abresch, Richard T et al. (2005) Body composition and water compartment measurements in boys with Duchenne muscular dystrophy. Am J Phys Med Rehabil 84:483-91
McDonald, Craig M; Widman, Lana; Abresch, R Ted et al. (2005) Utility of a step activity monitor for the measurement of daily ambulatory activity in children. Arch Phys Med Rehabil 86:793-801
McDonald, Craig M (2002) Physical activity, health impairments, and disability in neuromuscular disease. Am J Phys Med Rehabil 81:S108-20