Mechanical efficiency and balance in adolescents and young adults with cerebral palsy

Mechanical efficiency (ME) during stair-climbing measures ambulation ability. This study investigated the relationship between ME and age, anthropometric, functional walking, and balance parameters in 52 adolescents with cerebral palsy (CP), age 13.5-23.3 yrs, who participated in an intervention study to improve walking. Measurements included ME, 6-min and 10-m walk tests and the Berg balance scale (BBS). Walk test measures correlated significantly with ME, as expected, as did BBS (r=0.68) and age (r=0.51). The multiple correlation coefficient with both age and BBS increased to 0.80. The measurements were divided into two groups of low (<40, n=19) and high (>40, n=33) BBS scores. Repeating regression analyses, demonstrated that in the low BBS group ME was significantly related to BBS, but not age, in contrast to opposite results in the high BBS group. Regressions were calculated for each of the 14 items of the BBS with ME. For the whole group, 12 items correlated significantly, but only three in the high BBS group (one leg standing, reach while standing and tandem standing). In the low BBS group 10 of the items correlated significantly, with the former three ranking near the top. Balance is an important component of ambulation in children with CP. Mobility in those scoring>40 is related to age, but in those more deficient in balance (<40) mobility is more closely associated with balance than age. Effective therapy to improve walking in younger children might incorporate more balance-focused exercises, similar to those related to BBS items strongly associated with ME.