Background Some recreational runners with obesity successfully train or compete without musculoskeletal injury. Insight into the key kinetic strategies of injury‐free heavier runners is necessary to appropriately guide development of safe training programs for this population. Objective To determine key biomechanical strategies of running in individuals with body mass index (BMI) values above and equal to and higher than 30 kg/m2. Design This was a case‐control study. Participants Runners with obesity (n =18; 42.7 years, 38.9% women) who were matched by sex, age, footstrike type, footwear characteristics, and running speed with healthy runners (n = 36; 41.7 years, 32.5% women). Setting Research laboratory affiliated with an academic medical center. Methods A seven‐camera optical motion analysis system was used to capture running kinematics and an instrumented treadmill captured kinetic data. Main Outcomes Main outcomes were temporal spatial parameters, joint excursions, peak ground reaction forces (GRFs), joint moments, vertical average loading rate (VALR), impulses, and vertical stiffness (Kvert). Results Runners with obesity demonstrated 15% less vertical excursion of the center of mass, 18% wider strides, and 3% longer stance times than nonobese runners (P < .05). Normalized peak GRFs and VALRs were higher in the nonobese group. GRF impulse was higher in the group with obesity compared to the nonobese group (means ± SD; 339.6 ± 55.2 Ns vs. 255.0 ± 45.8 Ns; P = .0001). Kvert was higher in the obese group compared to the nonobese group (238.6 ± 50.3 N/cm vs. 183.1 ± 29.4 N/cm; P = .0001). Peak hip moments were higher in runners with obesity in the sagittal and frontal planes (P < .05). Conclusion Runners with obesity dampened impact forces and controlled loading rate more than nonobese runners by increasing lower body stiffness and constraining vertical displacement.

Introduction: The literature largely addresses questions of diagnostic accuracy and therapeutic accuracy. However, the magnitude of the clinical impact of syndesmosis injury is commonly described in intuitive yet qualitative terms. This systematic review aimed to quantify the impact of syndesmosis injury. Methods: Published clinical outcomes data were used to compute an effect size reflecting the impact of syndesmosis injury. This was done within the clinical contexts of isolated syndesmosis injury and syndesmosis injury with concomitant ankle fracture. Clinical outcomes data included Olerud-Molander (OM) and American Orthopaedic Foot and Ankle Society (AOFAS) scores, visual analog scale for pain, and days missed from sport competition. Parametric data were compared with Student t tests. Effect size was computed using Cohen’s d. Results: In ankle fracture patients, syndesmosis injury demonstrated a large effect size for OM (d = 0.96) and AOFAS (d = 0.83) scores. In athletic populations without concomitant ankle fracture, syndesmosis injury demonstrated a large effect size on days missed from competition (d = 2.32). Discussion: These findings confirm the magnitude of the negative impact of syndesmosis injury in athletic populations with isolated injury and in ankle fracture patients. In ankle fracture patients, this large negative effect remains despite surgery. Thus, syndesmosis repair may not fully mitigate the impact of the injury. Levels of Evidence: Level III: Systematic review

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Category: Ankle; Trauma Introduction/Purpose: Reported rates of syndesmosis malreduction are highly variable due to applied criteria that differ in imaging modality, threshold for malreduction and use of the contralateral ankle for comparison. Studies have emphasized the importance of anatomic reduction while providing inconclusive evidence for the need for revision surgery in malreduced ankles. With no industry standard for determining malreduction, it is unclear whether the most commonly used criteria is a valuable discriminator for clinical decision making. Our objective was to describe the rates of syndesmosis revision that are reported in the literature and to determine if malreduction diagnoses are reliable in predicting the need for syndesmosis revision surgery. Methods: Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta Analyses) guidelines, a systematic review of the literature was performed in order to describe revision syndesmosis surgery. Included studies were grouped based on criteria for determining malreduction - group 1 (N = 954) used unilateral radiograph, group 2 (N = 41) used unilateral CT scan, group 3 (N =531) used bilateral CT scan and group 4 (N = 119) used bilateral radiograph. Evidentiary quality was graded with the Modified Coleman Methodology Score (MCMS). Student t tests were used to calculate the differences between groups for rates of malreduction and revision. For the screening criteria most commonly used to determine malreduction, the test characteristics sensitivity, specificity and positive predictive value (PPV) were calculated. Results: Pooled rates of malreduction and revision for the groups using CT scan (groups 2 and 3, N = 572, mean follow up 16 months) were 23.5% and 0.25% respectively. Pooled rates of malreduction and revision for the groups using bilateral imaging (groups 3 and 4, N = 650, mean follow up 20 months) were 18.5% and 0.8% respectively. Significant differences were found between CT scan and radiograph for malreduction (p<0.001) and for revision (p=0.02). Significant differences were also found between bilateral and unilateral imaging for malreduction (p=0.01). The malreduction criteria of a 2mm difference in tibiofibular space on CT scan between the injured and uninjured side was used in 6 studies (N = 531, mean follow up 19 months). The sensitivity of this criteria for detecting cases which required revision was 100%, specificity 78%, and PPV 6%. Conclusion: It is unclear whether high rates of malreduction are due to suboptimal surgical repair which lead to clinical detriment or are they solely an imaging finding which depend heavily on the criteria for diagnosis. The most commonly used criteria for malreduction - a 2mm side-to-side difference in tibiofibular space on CT scan - is highly sensitive for reoperations. The specificity and PPV indicate that a threshold of more than 2mm is needed to better evaluate those ankles which may require revision surgery. Based on the current findings, malreduction diagnoses do not adequately translate from disease-oriented information to patient-oriented information.