Y-balance test performance and BMI are associated with ankle sprain injury in collegiate male athletes

Objectives: To determine if static balance, dynamic balance, ankle range of motion, body mass index (BMI), or history of an ankle sprain were associated with ankle sprain injuries within male and female collegiate athletes. Design: Prospective cohort. Methods: Three hundred and eighty-four male (age = 19.79 ± 1.80 years, height = 178.02 ± 10.39 cm, mass = 85.71 ± 17.59 kg) and one hundred and sixty seven female (age = 19.80 ± 1.52 years, height = 165.61 ± 7.08 cm, mass = 66.16 ± 10.53 kg) collegiate athletes involved in a variety of sports at a NCAA Division II or NAIA institution participated. Baseline measures of the Y-Balance (YBT), modified Balance Error Scoring System (mBESS), weight-bearing lunge test (WBLT), BMI, and history of ankle sprain were recorded. Participants were followed prospectively for two years and incidence of ankle sprain injury was documented. The average of the WBLT, mBESS, and YBT measures were used for analysis. Male and female participants were analyzed separately. Mann–Whitney U tests were utilized to identify variables which may be significantly associated with ankle sprain injury for logistic regression analysis. Results: A total of 59 (38 males and 21 females) individuals sustained an ankle sprain during the follow up period. The binary logistic regression revealed BMI (Nagelkerke R2 = 0.069; X2 = 12.89; p \u3c 0.001; OR = 3.85; 95% CI, 1.90–7.79; p \u3c 0.001) and anterior reach of the YBT (Nagelkerke R2 = 0.074; X2 = 13.70, p \u3c 0.001; OR = 3.64; 95% CI = 1.83–7.23; p = 0.01) were significantly associated with ankle sprain injury in male athletes. No variables were associated with ankle sprain injury within female athletes. Conclusions: Male collegiate athletes with greater BMI and lesser YBT anterior reach were at a greater risk of sustaining an ankle sprain injury

Anterior knee pain risk in male and female military tactical athletes

Context: Anterior knee pain (AKP) is ubiquitous in early career military members and exacerbated during functional tasks required during military duties. Therefore, it is important to understand the risk of this condition among male and female tactical athletes in diverse military occupations. Objective: To assess sex and occupation with respect to the AKP risk in military members. Design: Descriptive epidemiology study. Setting: United States Armed Forces. Patients or Other Participants: All military members diagnosed with anteropatellar or retropatellar pain, patellar instability, or knee tendinopathy on their initial encounter from 2006 to 2015. Main Outcome Measure(s): The Defense Medical Epidemiology Database was queried for the number of individuals with AKP. Relative risk (RR) and χ2 statistics were calculated in the assessment of sex and occupational category. Regressions were calculated to determine associations between service branch, sex, and AKP across time. Results: From 2006 to 2015, a total of 151 263 enlisted and 14 335 officer service members were diagnosed with AKP. Enlisted females had an incidence rate of 16.7 per 1000 person-years compared with enlisted males\u27 incidence rate of 12.7 per 1000 person-years (RR = 1.32; 95% CI = 1.30, 1.34; P\u3c.001) across all AKP diagnoses. Female officers had an incidence rate of 10.7 per 1000 person-years; male officers had an incidence rate of 5.3 per 1000 person-years (RR = 2.01; 95% CI = 1.94, 2.09). Differences in risk were also noted across military occupations for both enlisted and officer service members (P values,.05). Conclusions: Sex and military occupation were salient factors for the AKP risk. Evaluating training requirements and developing intervention programs across military occupations could serve as a focus for future research aiming to decrease the incidence of chronic knee pain

Pain severity during functional activities in individuals with patellofemoral pain: A systematic review with meta-analysis

OBJECTIVES: Patellofemoral pain (PFP) is a common lower extremity condition that results in pain during functional tasks. Currently, it is unknown the extent to which differences in pain levels exist in individuals with PFP compared to asymptomatic controls during functional task and if pain differ across various functional tasks. The purpose of this systematic review and meta-analysis is to evaluate pain levels between individuals with PFP and asymptomatic controls and compare pain severity across various functional tasks. DESIGN: Systematic review. METHODS: OVID, SPORTSDiscus, CINAHL, Web of Science and Embase were searched for studies that included PFP and asymptomatic controls with pain assessed during a functional task. Pooled pain scores mean with 95% confidence intervals were calculated between groups across 11 functional tasks. Standardized mean differences (SMD) were calculated based on Hedge\u27s g effect sizes. Tasks whose SMD 95% confidence intervals were non-overlapping were considered significantly different. RESULTS: 28 articles were included for data analysis. Pain was greater across 10 tasks (SMD = 1.52-6.08) in individuals with PFP compared to the asymptomatic controls with an average SMD of 2.45. Running and star excursion balance testing resulted in greater pain than walking. Limited evidence showed greater pain in sitting than seven other tasks. CONCLUSIONS: Moderate evidence exists for greater pain levels in individuals with PFP compared to asymptomatic controls in functional tasks. Pain was greater during running and star excursion balance compared to walking. Clinicians should assess knee pain before and after functional tasks to improve our understanding of patient specific pain experiences

Lower extremity muscle activation and knee flexion during a jump-landing task

Context: Decreased sagittal-plane motion at the knee during dynamic tasks has been reported to increase impact forces during landing, potentially leading to knee injuries such as anterior cruciate ligament rupture. Objective: To describe the relationship between lower extremity muscle activity and knee-flexion angle during a jump-landing task. Design: Cross-sectional study. Setting: Research laboratory. Patients or Other Participants: Thirty recreationally active volunteers (15 men, 15 women: age = 21.63 ± 2.01 years, height = 173.95 ± 11.88 cm, mass = 72.57 ± 14.25 kg). Intervention(s): Knee-flexion angle and lower extremity muscle activity were collected during 10 trials of a jump-landing task. Main Outcome Measure(s): Simple correlation analyses were performed to determine the relationship between each knee-flexion variable (initial contact, peak, and displacement) and electromyographic amplitude of the gluteus maximus (GMAX), quadriceps (VMO and VL), hamstrings, gastrocnemius, and quadriceps : hamstring (Q : H) ratio. Separate forward stepwise multiple regressions were conducted to determine which combination of muscle activity variables predicted each knee-flexion variable. Results: During preactivation, VMO and GMAX activity and the Q : H ratio were negatively correlated with knee-flexion angle at initial contact (VMO: r =-0.382, P = .045; GMAX: r = -0.385, P = .043; Q : H ratio: r =-0.442, P = .018). The VMO, VL, and GMAX deceleration values were negatively correlated with peak knee-flexion angle (VMO: r =-0.687, P = .001; VL: r =-0.467, P = .011; GMAX: r =-0.386, P = .043). The VMO and VL deceleration values were negatively correlated with knee-flexion displacement (VMO: r =-0.631, P = .001; VL: r = -0.453, P = .014). The Q : H ratio and GM activity predicted 34.7% of the variance in knee-flexion angle at initial contact (P = .006). The VMO activity predicted 47.1% of the variance in peak knee-flexion angle (P = .001). The VMO and VL activity predicted 49.5% of the variance in knee-flexion displacement (P = .001). Conclusions: Greater quadriceps and GMAX activation and less hamstrings and gastrocnemius activation were correlated with smaller knee-flexion angles. This landing strategy may predispose an individual to increased impact forces due to the negative influence on knee-flexion position. © by the National Athletic Trainers\u27 Association, Inc

Effect of Limiting Ankle-Dorsiflexion Range of Motion on Lower Extremity Kinematics and Muscle-Activation Patterns During a Squat

Context: Limitations in gastrocnemius/soleus flexibility that restrict ankle dorsiflexion during dynamic tasks have been reported in individuals with patellofemoral pain (PFP) and are theorized to play a role in its development. Objective: To determine the effect of restricted ankle-dorsiflexion range of motion (ROM) on lower extremity kinematics and muscle activity (EMG) during a squat. The authors hypothesized that restricted ankle-dorsiflexion ROM would alter knee kinematics and lower extremity EMG during a squat. Design: Cross-sectional. Participants: 30 healthy, recreationally active individuals without a history of lower extremity injury. Interventions: Each participant performed 7 trials of a double-leg squat under 2 conditions: a nowedge condition (NW) with the foot flat on the floor and a wedge condition (W) with a 12° forefoot angle to simulate reduced plantar-flexor flexibility. Main Outcome Measures: 3-dimensional hip and knee kinematics, medial knee displacement (MKD), and ankle-dorsiflexion angle. EMG of vastus medialis oblique (VMO), vastus lateralis (VL), lateral gastrocnemius (LG), and soleus (SOL). One-way repeated-measures ANOVAs were performed to determine differences between the W and NW conditions. Results: Compared with the NW condition, the wedge produced decreased peak knee flexion (P < .001, effect size [ES] = 0.81) and kneeflexion excursion (P < .001, ES = 0.82) while producing increased peak ankle dorsiflexion (P = .006, ES = 0.31), ankle-dorsiflexion excursion (P < .001, ES = 0.31), peak knee-valgus angle (P = .02, ES = 0.21), and MKD (P < .001, ES = 2.92). During the W condition, VL (P = 0.002, ES = 0.33) and VMO (P = .049, ES = 0.20) activity decreased while soleus activity increased (P = .03, ES = 0.64) compared with the NW condition. No changes were seen in hip kinematics (P > .05). Conclusions: Altering ankle-dorsiflexion starting position during a double-leg squat resulted in increased knee valgus and MKD, as well as decreased quadriceps activation and increased soleus activation. These changes are similar to those seen in people with PFP

Lower Extremity Muscle Activation and Knee Flexion During a Jump-Landing Task

Decreased sagittal-plane motion at the knee during dynamic tasks has been reported to increase impact forces during landing, potentially leading to knee injuries such as anterior cruciate ligament rupture

Various methods for assessing static lower extremity alignment: Implications for prospective risk-factor screenings

Context: Accurate, efficient, and reliable measurement methods are essential to prospectively identify risk factors for knee injuries in large cohorts. Objective: To determine tester reliability using digital photographs for the measurement of static lower extremity alignment (LEA) and whether values quantified with an electromagnetic motion-tracking system are in agreement with those quantified with clinical methods and digital photographs. Design: Descriptive laboratory study. Setting: Laboratory. Patients or Other Participants: Thirty-three individuals participated and included 17 (10 women, 7 men; age = 21.7 ± 2.7 years, height= 163.4 ± 6.4 cm, mass= 59.7 ± 7.8 kg, body mass index = 23.7 ± 2.6 kg/m2) in study 1, in which we examined the reliability between clinical measures and digital photographs in 1 trained and 1 novice investigator, and 16 (11 women, 5 men; age = 22.3 ± 1.6 years, height = 170.3 ± 6.9 cm, mass = 72.9 ± 16.4 kg, body mass index = 25.2 ± 5.4 kg/m2) in study 2, in which we examined the agreement among clinical measures, digital photographs, and an electromagnetic tracking system. Intervention(s): We evaluated measures of pelvic angle, quadriceps angle, tibiofemoral angle, genu recurvatum, femur length, and tibia length. Clinical measures were assessed using clinically accepted methods. Frontal- and sagittal-plane digital images were captured and imported into a computer software program. Anatomic landmarks were digitized using an electromagnetic tracking system to calculate static LEA. Main Outcome Measure(s): Intraclass correlation coefficients and standard errors of measurement were calculated to examine tester reliability. We calculated 95% limits of agreement and used Bland-Altman plots to examine agreement among clinical measures, digital photographs, and an electromagnetic tracking system. Results: Using digital photographs, fair to excellent intratester (intraclass correlation coefficient range = 0.70-0.99) and intertester (intraclass correlation coefficient range = 0.75-0.97) reliability were observed for static knee alignment and limblength measures. An acceptable level of agreement was observed between clinical measures and digital pictures for limb-length measures. When comparing clinical measures and digital photographs with the electromagnetic tracking system, an acceptable level of agreement was observed in measures of static knee angles and limb-length measures. Conclusions: The use of digital photographs and an electromagnetic tracking system appears to be an efficient and reliable method to assess static knee alignment and limb-length measurements. © by the National Athletic Trainers\u27 Association, Inc