Donald L. Goss

A Comparison of Negative Joint Work and Vertical Ground Reaction Force Loading Rates in Chi Runners and Rearfoot-Striking Runners

STUDY DESIGN Observational. OBJECTIVES To compare lower extremity negative joint work and vertical ground reaction force loading rates in rearfoot-striking (RS) and Chi runners. BACKGROUND Alternative running styles such as Chi running have become a popular alternative to RS running. Proponents assert that this running style reduces knee joint loading and ground reaction force loading rates. METHODS Twenty-two RS and 12 Chi runners ran for 5 minutes at a self-selected speed on an instrumented treadmill. A 3-D motion analysis system was used to obtain kinematic data. Average vertical ground reaction force loading rate and negative work of the ankle dorsiflexors, ankle plantar flexors, and knee extensors were computed during the stance phase. Groups were compared using a 1-way analysis of covariance for each variable, with running speed and age as covariates. RESULTS On average, RS runners demonstrated greater knee extensor negative work (RS, -0.332 J/body height × body weight [BH·BW]; Chi, -0.144 J/BH·BW; P<.001), whereas Chi runners demonstrated more ankle plantar flexor negative work (Chi, -0.467 J/BH·BW; RS, -0.315 J/BH·BW; P<.001). RS runners demonstrated greater average vertical ground reaction force loading rates than Chi runners (RS, 68.6 BW/s; Chi, 43.1 BW/s; P<.001). CONCLUSION Chi running may reduce vertical loading rates and knee extensor work, but may increase work of the ankle plantar flexors.

Lower Extremity Biomechanics and Self-Reported Foot-Strike Patterns Among Runners in Traditional and Minimalist Shoes

CONTEXT The injury incidence rate among runners is approximately 50%. Some individuals have advocated using an anterior-foot-strike pattern to reduce ground reaction forces and injury rates that they attribute to a rear-foot-strike pattern. The proportion of minimalist shoe wearers who adopt an anterior-foot-strike pattern remains unclear. OBJECTIVE To evaluate the accuracy of self-reported foot-strike patterns, compare negative ankle- and knee-joint angular work among runners using different foot-strike patterns and wearing traditional or minimalist shoes, and describe average vertical-loading rates. DESIGN Descriptive laboratory study. SETTING Research laboratory. PATIENTS OR OTHER PARTICIPANTS A total of 60 healthy volunteers (37 men, 23 women; age = 34.9 ± 8.9 years, height = 1.74 ± 0.08 m, mass = 70.9 ± 13.4 kg) with more than 6 months of experience wearing traditional or minimalist shoes were instructed to classify their foot-strike patterns. INTERVENTION(S) Participants ran in their preferred shoes on an instrumented treadmill with 3-dimensional motion capture. MAIN OUTCOME MEASURE(S) Self-reported foot-strike patterns were compared with 2-dimensional video assessments. Runners were classified into 3 groups based on video assessment: traditional-shoe rear-foot strikers (TSR; n = 22), minimalist-shoe anterior-foot strikers (MSA; n = 21), and minimalist-shoe rear-foot strikers (MSR; n = 17). Ankle and knee negative angular work and average vertical-loading rates during stance phase were compared among groups. RESULTS Only 41 (68.3%) runners reported foot-strike patterns that agreed with the video assessment (κ = 0.42, P < .001). The TSR runners demonstrated greater ankle-dorsiflexion and knee-extension negative work than MSA and MSR runners (P < .05). The MSA (P < .001) and MSR (P = .01) runners demonstrated greater ankle plantar-flexion negative work than TSR runners. The MSR runners demonstrated a greater average vertical-loading rate than MSA and TSR runners (P < .001). CONCLUSIONS Runners often cannot report their foot-strike patterns accurately and may not automatically adopt an anterior-foot-strike pattern after transitioning to minimalist running shoes.

Fracture of the Scaphoid During a Bench-Press Exercise

The patient was a 21-year-old male cadet at a military academy who was evaluated by a physical therapist in a direct-access capacity for a chief complaint of left wrist pain that began 1 day after injuring his wrist while performing a bench-press exercise. Due to concern for a scaphoid fracture and because radiographic imaging was not immediately available, a physical therapist credentialed to utilize fluoroscopy evaluated the left wrist. Radiographs were subsequently ordered, which confirmed a mid-waist, nondisplaced scaphoid fracture.

Glenohumeral Dislocation With Engaging Hill-Sachs Lesion

A 20-year-old military cadet injured his left shoulder after landing in an abducted and externally rotated arm position while participating in a mandatory obstacle course. Following examination, the individual was taken to the emergency department, where radiographs confirmed an anterior dislocation of the glenohumeral joint and a large Hill-Sachs lesion wedged on the glenoid. Results of noncontrast magnetic resonance imaging and a computed tomography scan confirmed the presence of a large Hill-Sachs lesion. J Orthop Sports Phys Ther 2018;48(1):50. doi:10.2519/jospt.2018.7609.

Evaluation of a Novel Field Expedient Musculoskeletal Readiness Screening Tool in an Army Basic Training Population

BACKGROUND Musculoskeletal injuries present a significant challenge to military readiness accounting for over 29% of ambulatory medical visits and 25 million limited duty days across the U.S. Army. Although U.S. Military Health Systems perform periodic general health and deployment assessments, there is no validated tool to determine when a service member is at increased risk of sustaining a musculoskeletal injury. METHOD 292 U.S. Army basic training recruits completed a novel injury screening test called the Musculoskeletal Readiness Screening Tool (MRST). It consisted of six separate physical movements and asked one question regarding perceived risk of personal injury. The injury surveillance period covered the duration of the basic training program lasting from 9 to 20 weeks. An independent t test was performed to assess for differences in composite MRST scores between those who sustained an injury and those who did not. A Receiver Operator Characteristic curve analysis was completed to determine if an appropriate cutoff score existed to predict increased likelihood for sustaining an injury within this cohort. RESULTS Our results indicate that the difference in mean composite score between injured (n = 143) and noninjured subjects fell just short of being significantly different (p = 0.053). The MRST is most specific with a cutoff score of 6 (out of a maximum score of 12) at 0.89 (95% confidence interval: 0.82, 0.93). Those scoring less than or equal to 6 on the screening tool were 2.05 times (95% confidence interval: 1.07, 3.9) as likely to sustain an injury as those scoring greater than 6. Additionally, the results indicate that the test can be applied to both male and female trainees, as scores were not significantly different between the sexes. CONCLUSION The MRST shows potential as a tool for identifying service members at higher risk for sustaining a musculoskeletal injury. Further research is needed to assess the validity, reliability, and responsiveness of this novel screening tool.

Extradural Cystic Lesion

A 21-year-old male military academy cadet was evaluated in a physical therapy clinic for worsening lower back pain 2 months after picking up a dumbbell. Following examination and follow-up, the therapist ordered radiographs and referred the patient to primary care due to worsening symptoms. Magnetic resonance imaging ordered by the physician revealed an extradural cystic lesion. J Orthop Sports Phys Ther 2017;47(5):368. doi:10.2519/jospt.2017.6584.

The Musculoskeletal Readiness Screening Tool- Injury Predictor for United States Military Academy Preparatory Cadets?: 3061 Board #126 June 3, 3: 30 PM - 5: 00 PM.

Abstract : Unique aspects of military service put our nations military at increased risk for injury that may not already be captured in the FMS and other injury prediction tools. The Musculoskeletal Readiness Screening Tool (MRST) was developed to combine evidence from physical performance tests used to predict injury and tasks unique to military personnel. Tests include the weight bearing forward lunge, modified deep squat, closed kinetic chain upper extremity stability test (CKCUEST), forward step down with eyes closed, stationary tuck jump, unilateral wall sit hold, and individual perceived level of risk for injury. The Feagin hop and self-reported history of injury were added to the screen. PURPOSE: To examine whether MRST scores, as a composite or further broken down into individual components, were predictive of a United States Military Academy Preparatory School (USMAPS) cadet candidate sustaining a future musculoskeletal injury.