The effects of neurodynamic straight leg raise treatment duration on range of hip flexion and protective muscle activity at P1

Study design: Randomized, single blind, same subject crossover trial. Objectives: To compare the effects of two neurodynamic treatment doses on range of hip flexion (ROM HF) and electromyographic (EMG) activity of semitendinosus, at first onset of pain (P1). Methods: A total of 26 healthy participants without low back or leg pain received each treatment in a random order with at least 48 hours between sessions. Baseline ROM HF and EMG magnitude of semitendinosus at P1 were collected. Subjects then received either 3 x 1 or 3 x 2 minutes of oscillating end of range (grade IV+) straight leg raise (SLR) neurodynamic treatment and were re-assessed for baseline measures. Results: There was no significant difference between groups in EMG magnitude (P=0.190) and ROM HF (P=0.739) at P1. There was also no significant difference within groups in EMG magnitude at P1 (P=0.182); however, there was a significant improvement in ROM HF at P1 in both groups compared to baseline readings (P=0.000), with increases of 6.7 degrees and 5.1 degrees for the 3 x 1- and 3 x 2-minute groups, respectively. Conclusion: Findings indicate that 3 x 2 minutes of oscillating grade IV+ SLR neurodynamic treatment has no additional benefit over 3 x 1 minute, on ROM HF or EMG magnitude of semitendinosus at P1. Using an oscillating SLR treatment may, however, help to increase pain-free ROM HF, although further studies are necessary to confirm this.