Muscle strength during active straight leg raising correlates with walking capacity in patients with lumbar spinal canal stenosis with neurogenic intermittent claudication

[Purpose] The purpose of this study was to investigate the factors related to walking capacity (WC) reflecting neurogenic intermittent claudication (IC). [Subjects and Methods] We selected 56 female patients (69.6 ± 8.0 years) with Lumber Spinal Canal Stenosis (LCS) with IC. We measured WC on a flat floor, and demonstrated that 3factors predict the relationship with IC as follows: trunk forward bending in the standing position (finger-floor distance), muscle strength during active straight leg raising (ASLR) on the symptomatic side, and the degree of subjective pain soon after standing upright for 30 s. [Results] WC and muscle strength in ASLR were not affected by age. WC was correlated with ASLR strength. [Conclusion] These results suggest that the motion of ASLR leads tocanal or foraminal stenosis, and that this test will be useful for patients with LCS.