The inter-rater reliability of clinical observation of prone hip extension and association between aberrant movement and chronic low back pain.

BACKGROUND: Clinical observation of aberrant movement patterns during prone hip extension (PHE) is commonly used in clinical practice to identify patients with low back pain. It could be clinically useful to identify individuals with chronic low back pain during remission (CLBPremission) to provide proactive intervention to prevent exacerbation of low back symptoms. OBJECTIVES: This study aimed to establish inter-rater reliability of clinical observation of PHE and association between aberrant movement pattern and CLBPremission. DESIGN: A cross-sectional study. METHOD: Twenty-six participants with CLBPremission and 18 participants without history of low back pain (NoLBP) performed 3 repetitions of active PHE, while 2 examiners concurrently observed and independently rated the movements as "presence" or "absence" of aberrant movement. Kappa statistics were used to establish inter-rater reliability based on rating data from 2 examiners, while chi-square tests were used to determine the association between aberrant movement and CLBPremission based on ratings (presence and absence) and known groups (CLBPremission and NoLBP). RESULTS: Kappa values ranged from fair to moderate (Kappa = 0.36-0.58). Result also demonstrated a significant association (P < 0.05) between presence of aberrant movement and CLBPremission. Findings indicate fair to moderate inter-rater reliability which are sufficient for clinical practice. The findings also indicated presence of aberrant movement patterns during active PHE was associated with CLBPremission. CONCLUSIONS: These findings suggested the usefulness of clinical observation of aberrant movement pattern during PHE to identify CLBPremission. The detection of aberrant movement would help clinicians to provide preventive program to minimize the risk of recurrent episodes of low back symptoms.

Effect of increased relative stiffness of the lumbar spine on hamstring muscle stretching in individuals with a history of low back pain suspected to have a clinical lumbar instability: A randomized crossover design.

BACKGROUND: Theoretically, lumbopelvic stabilization techniques during hamstring muscle stretching could increase lumbar stiffness relative to hamstring muscle in individuals with a history of low back pain and suspected clinical lumbar instability. However, evidence to support this theory is limited. This study aimed to 1) determine changes in lumbopelvic, lumbar, and hip motions, and hamstring muscle length after stretching exercises with lumbopelvic stiffening or relaxing techniques, and 2) compare those changes between techniques. METHODS: This study used a randomized crossover design. Thirty-two participants with a history of low back pain and bilateral hamstring muscle tightness were recruited. The order of the first technique was randomly assigned. After a 2-day washout, participants were crossed over to the second technique. Motion data during active forward trunk bending and bilateral hamstring muscle length during passive knee extension were collected pre- and post-intervention. FINDINGS: Significant increases (P < 0.05) were found in bilateral hamstring muscle length for both techniques. However, stiffening technique demonstrated a significant decrease in lumbar motion (P < 0.05) and increase in hip motion (P < 0.05), while relaxing technique demonstrated trends showing increases in lumbar and hip motions (P = 0.134 and 0.115, respectively). The findings showed significantly greater improvement (P < 0.05) in lumbar and hip motions with stiffening technique. INTERPRETATION: The findings suggest increased relative stiffness of the lumbar spine during hamstring muscle stretching can specifically lengthen bilateral hamstring muscle and decrease excessive lumbar motion. This stiffening technique may prevent excessive movement of the lumbar spine, thereby reducing the risk of recurrent low back pain.