Running Mechanics After Repeated Sprints in Femoroacetabular Impingement Syndrome, Cam Morphology, and Controls

Abstract

Background: People with femoroacetabular with femoroacetabular impingement syndrome (FAIS) often report pain during sports involving repeated sprinting. It remains unclear how sports participation influences running biomechanics in individuals with FAIS. Hypothesis: Changes in running biomechanics and/or isometric hip strength after repeated sprint exercise would be greatest in individuals with FAIS compared with asymptomatic individuals with (CAM) and without cam morphology (Control). Study Design: Controlled laboratory study. Level of Evidence: Level 3. Methods: Three-dimensional hip biomechanics during maximal running (10 m) and hip strength were measured in 49 recreationally active individuals (FAIS = 15; CAM = 16; Control = 18) before and after repeated sprint exercise performed on a nonmotorized treadmill (8-16 × 30 m). Effects of group and time were assessed for biomechanics and strength variables with repeated-measures analyses of variance. Relationships between hip pain (Copenhagen Hip and Groin Outcome Score) and changes in hip moments and strength after repeated sprint exercise were determined using Spearman’s correlation coefficients (ρ). Results: Running speed, hip flexion angles, hip flexion and extension moments, and hip strength in all muscle groups were significantly reduced from pre to post. No significant between-group differences were observed before or after repeated sprint exercise. No significant relationships (ρ = 0.04-0.30) were observed between hip pain and changes in hip moments or strength in the FAIS group. Conclusion: Changes in running biomechanics and strength after repeated sprint exercise did not differ between participants with FAIS and asymptomatic participants with and without cam morphology. Self-reported pain did not appear to influence biomechanics during running or strength after repeated sprint exercise in participants with FAIS. Clinical Relevance: A short bout of repeated sprinting may not elicit changes in running biomechanics in FAIS beyond what occurs in those without symptoms. Longer duration activities or activities requiring greater hip flexion angles may better provoke pathology-related changes in running biomechanics in people with FAIS.

Hip Contact Forces During Sprinting in Femoroacetabular Impingement Syndrome

“…Further attempts were performed if measured force increased by >15% in the second trial compared with the first trial. For the purpose of EMG normalization (28), participants also performed a maximal 30-m sprint on a nonmotorized treadmill (17). The trial with the highest EMG amplitude was used for normalization.…”

“…With an alpha of 0.05 and a power of 0.8, 8 to 14 participants were required per group. Forty-six recreationally active individuals concurrently enrolled in a larger study (17) were allocated to FAIS ( n = 14), CAM ( n = 15), or control ( n = 17) groups based on their history of hip and groin symptoms, results of a clinical examination, and alpha angle measurements from magnetic resonance imaging (MRI; see details in the Magnetic resonance imaging section). Participants were assigned to the FAIS group if they had hip or groin pain for more than 3 months, a positive clinical impingement test (i.e., FADIR and FABER) (20), and evidence of cam morphology on MRI (alpha angle >55° (20)).…”

“…This study aimed to 1) compare hip contact forces (magnitude and direction) during sprinting between individuals with FAIS, asymptomatic cam morphology (CAM), and controls without cam morphology, and 2) identify the phases of sprinting with high levels of anteriorly directed hip contact forces. Methods: Forty-six recreationally active individuals with comparable levels of physical activity were divided into three groups (FAIS,14; CAM,15; control,17) based on their history of hip/groin pain, results of clinical impingement tests, and presence of cam morphology (alpha angle >55°). Three-dimensional marker trajectories, ground reaction forces, and electromyograms from 12 lower-limb muscles were recorded during 10-m overground sprinting trials.…”

“…Sprinting requires large hip flexion angles, limb speeds, and muscle forces, especially during acceleration (16). This secondary analysis of a previously published dataset (17) aimed to compare the magnitude and direction of hip contact forces developed during sprinting between individuals with FAIS and asymptomatic cam morphology (CAM), and individuals with FAIS and asymptomatic controls without cam morphology (control). Because individuals with FAIS have been shown to exhibit different muscle activation patterns compared with asymptomatic individuals without cam morphology (18), an electromyography (EMG)informed neuromusculoskeletal model (5,6) was used to estimate hip contact forces for each group.…”