ILIAC CREST HEIGHT DIFFERENCE AND OTHER RUNNING-RELATED VARIABLES' RELATIONSHIP WITH RUNNING INJURY.

BACKGROUND: Leg-length inequality (LLI) is a common condition that may contribute to various spinal, pelvic, and lower extremity dysfunctions. Iliac crest height difference (ICHD) has been demonstrated to be a good estimate for LLI and may be a useful measure for identifying individuals who are at risk for injury. PURPOSE: To investigate the relationship between ICHD and other running-related variables with running injury. METHODS: An observational retrospective case-control design was used. Data were collected via questionnaire and physical examination from a purposive sample of 100 runners and were analyzed using chi-squared tests of independence. RESULTS: The prevalence of ICHD ≥ 5mm reported by subjects via questionnaire was ∼40%. There was no difference in report of injury between subjects with ICHD >5mm and those with ICHD <5mm (χ2 = 0.02, p = 0.88); however, lifetime history of injury (χ2 = 15.68, p = 0.00) and the number of running events participated (χ2 = 3.09, p = 0.04) were significant factors associated with injury; although not significant, there was a trend towards relationship with gender (χ2 = 3.2, = 0.07). CONCLUSION: Small ICHD is not associated with running injury among recreational runners. There appears to be an increased risk of running injury among runners who participate in more than one running event annually and those that have had a past history of running injury. Also, males may be at slightly greater risk of sustaining a running injury compared to females. LEVEL OF EVIDENCE: Therapy, level 3b.

PAIN AND PHYSICAL PERFORMANCE AMONG RECREATIONAL RUNNERS WHO RECEIVE A CORRECTION FOR AN ILIAC CREST HEIGHT DIFFERENCE: A CASE SERIES.

BACKGROUND: Leg-length inequality (LLI) is a musculoskeletal condition where one lower extremity is longer than the other. There is conflicting evidence on the relevance of LLI and conservative treatment options. Iliac crest height difference (ICHD) is a good estimate of LLI. OBJECTIVE: To observe changes in pain and performance among recreational runners with running-induced lower extremity pain who received ICHD correction. METHODS: A 12-week case series with multiple baseline and intervention (A-B-A-B) phases was used to observe the effects of ICHD correction on pain and performance among three symptomatic recreational runners. Primary outcome measures included the Lower Extremity Functional Scale (LEFS), the Visual Analog Scale -Worst Pain (VAS-W), symptom-free running distance, and average running speed. A standardized procedure for fabricating an in-shoe shim was utilized for ICHD correction. RESULTS: There were no clinically important differences in functional capacity for any subject between any phases. Also, two subjects demonstrated trends towards increased pain over the 12-week experimental period, whereas one subject demonstrated a decrease. One subject demonstrated a statistically significant increase in running distance during intervention phases, but the others demonstrated reductions. All subjects demonstrated trends towards increased running speed, but none were statistically significant. CONCLUSION: The correction of small ICHD < 9mm did not improve pain or performance among recreational runners. Individuals with small ICHD may be able to effectively compensate for lower extremity asymmetries; therefore, correction seems to be unnecessary and potentially harmful in short-term. LEVEL OF EVIDENCE: Therapy, level 4.