Contribution of aerobic fitness and back strength to lift capacity.
Matheson LN, Mooney V, Leggett S, Karen Schneider, Mayer JM. Spine (in press).

Study Design: This study used a concurrent validity regression design with 45 healthy female participants to study the contributions of aerobic capacity and back strength to lift capacity.

Objectives: The objective of this study was to measure the relative contributions of aerobic capacity and back strength to lift capacity.

Summary of Background Data: This was the first concurrent study of the relationships among spinal strength, aerobic capacity, and lift capacity. Previous research has demonstrated moderate to strong relationships between spinal strength and lift capacity and between aerobic capacity and lift capacity.
Methods: Multiple regression techniques were used with established reliable and valid measures of each construct to study the individual and joint contributions of spinal strength and aerobic capacity to lift capacity.

Results: Both spinal strength and aerobic capacity make significant independent contributions to lift capacity, accounting for 11% and 27% of the variance, respectively. Taken together, the predictive power of these variables on lift capacity is increased, accounting for 43% of the variance.

Conclusions:
 Lift capacity is dependent on both back strength and aerobic capacity. It may be inappropriate to use lift capacity as an indicator of the severity of spinal impairment in a disability determination system without taking into account the individual’s aerobic capacity. Treatment that is intended to improve the lift capacity of persons with spinal impairment should anticipate that both improvement in back strength and aerobic capacity would improve lift capacity.