Reliability and practicability of the straight leg raise test in children with cerebral palsy

Preventing restrictions to lower limb movement is part of the treatment given to children with cerebral palsy (CP). Such restrictions can be assessed using the 'straight leg raise' (SLR) test. This study investigated the interrater reliability and practicability of the SLR test in children with CP.

Experienced physiotherapists examined 23 children with CP (6-18y; eight females, 15 males) twice. The SLR hip range of motion (ROM) was measured using an electrogoniometer, and the test was rated based on sensitizing manoeuvres and biceps femoris muscle activity. Practicability was investigated by evaluating children's subjective feedback on the tolerable ROM.

Intraclass correlation coefficients for the SLR hip ROM varied, ranging from 0.84 (95% CI 0.61-0.93) to 0.93 (95% CI 0.87-0.96). Physiotherapists substantially agreed on SLR ratings (Cohen's kappa=0.73). Biceps femoris muscle activity decreased significantly with the release of tension on the sciatic nerve. All children were able to communicate the location and sensation of the maximally tolerated position.

The SLR test proved to be reliable and practicable in children with CP and might improve clinical reasoning processes. Lower limb movement restrictions in these children may partly be related to limitations in sciatic nerve mobility. Further studies should investigate if the SLR test could estimate activities in children with CP.