Basketball Players' Dynamic Performance Across Competition Levels.

Bullock, GS, Arnold, TW, Plisky, PJ, and Butler, RJ. Basketball players' dynamic performance across competition levels. J Strength Cond Res 32(12): 3537-3542, 2018-Dynamic balance is an integral component in screening lower extremity injury risk. Previous research has identified the need to create sport- and competition level-specific dynamic balance injury cut points. The purpose of this study was to determine if dynamic balance differences exist, using the Lower Quarter Y Balance Test (YBT-LQ), across varying competition levels (middle school, high school, college, and professional), in basketball players. Subjects were participating at the middle school (MS; n = 88), high school (HS; n = 105), college (COL; n = 46), and professional levels (PRO; n = 41). Statistical analysis was completed with a series of analysis of variance tests. Tukey post hoc tests were used to identify specific group-to-group differences if statistical significance (p ≤ 0.05) was observed. Effect size indices (ESI) were also calculated to provide an estimate of the clinical relevance. In the anterior reach, HS basketball players performed statistically better than the MS and COL (p < 0.01, ESI = 0.58) athletes, and all these groups performed better than the PRO basketball players (p < 0.01, ESI = 1.72). For the posteromedial, posterolateral reach directions and the composite score, the HS, COL, and PRO basketball players were not significantly different from each other; however, the HS group did reach further than the MS group (p < 0.01-0.02, ESI = 0.40-0.55). The PRO basketball players exhibited a lower asymmetrical total score compared with MS, HS, and COL players (p < 0.01-0.02, ESI = 0.52-0.68). Different competition levels displayed varying dynamic balance strategies. Creating basketball competition levels normative values for dynamic balance could help define injury risk cut points.

The Relationship Between Trunk Rotation, Upper Quarter Dynamic Stability, and Pitch Velocity.

Bullock, GS, Schmitt, AC, Chasse, PM, Little, BA, Diehl, LH, and Butler, RJ. The relationship between trunk rotation, upper quarter dynamic stability, and pitch velocity. J Strength Cond Res 32(1): 261-266, 2018-Understanding the relationship between upper quarter mobility, dynamic stability, and pitching velocity may be beneficial in elucidating underlying factors that affect pitching performance. The purpose of this study was to investigate upper trunk rotation mobility and upper quarter dynamic stability and their correlation to pitch velocity in NCAA Division I collegiate pitchers. We hypothesized that collegiate pitchers with greater upper trunk rotation mobility and upper extremity dynamic stability would exhibit higher pitching velocity. Trunk rotation and the Upper Quarter Y-Balance Test (YBT-UQ) were measured using standardized protocols. Collegiate pitchers (N = 30) then proceeded to complete their team prescribed dynamic and throwing warm-up followed by a pitching session from regulation distance at 100% effort. Each pitch was recorded for velocity and pitch type, only fastballs were used in analysis. The relationships between trunk rotation and fastball velocity, and YBT-UQ scores and fastball velocity were assessed using a series of 2-tail Pearson's correlations (p < 0.05). Throwing and nonthrowing sides (69.6 ± 9.5°, 70.7 ± 9.4°) had similar trunk rotation mobility. No statistically significant correlation between upper trunk rotation mobility and pitch velocity was found (throwing arm: r = 0.131; p < 0.491; nonthrowing arm: r = 0.135; p < 0.478). There was also no correlation between the YBT-UQ and fastball velocity. In this study of Division I baseball pitchers, we found no relationship between trunk rotational mobility, upper quarter dynamic stability, and pitching velocity. This suggests that increased upper extremity stability and trunk mobility are not directly related to fastball velocity. Understanding factors that associate to velocity may be helpful in predicting pitching performance.

Examining Differences in Movement Competency in Professional Baseball Players Born in the United States and Dominican Republic.

CONTEXT: Dominican Republic (DR) players have different training norms, which can affect their resiliency and performance. The variance among DR players' training regimens may be influenced by the degree of training incorporating fundamental movement patterns. OBJECTIVE: To examine differences in fundamental movement patterns in United States (US)-born versus DR-born professional baseball players. DESIGN: Cross-sectional cohort. SETTING: Professional baseball athletic training room. PARTICIPANTS: One hundred forty-two players (76 DR-born and 66 US-born) who were recently selected by a Major League Baseball team. INTERVENTION: Subjects completed the Functional Movement Screen using the standardized 7 movement tests and the 3 isolated clearing tests. MAIN OUTCOME MEASURES: The primary variables studied were composite score, left and right asymmetry, and individual movement standard scores. Two-way chi-squared analysis was utilized for the statistical analysis with statistical significance being identified at P < .05. RESULTS: DR players had a larger number of 1s (7.8% vs 3.0%) and 3s (10.5% vs 1.5%) on the right-sided hurdle step and a greater percentage of 3s (82.8% vs 60.6%) on right-sided shoulder mobility. US players had a larger percentage of 3s (33.3% vs 13.4%) and a lower percentage of 1s (2.2% vs 15.1%) on the active straight leg raise and a greater percentage of passable scores (≥2; 99.5% vs 65.8%) on the trunk stability push-up. CONCLUSION: This study suggests that fundamental movement competency differs between US- and DR-born professional baseball players. Based on these movement competency differences, a player's country of origin may be taken into account to create an effective training program.

Examining Fundamental Movement Competency and Closed-Chain Upper-Extremity Dynamic Balance in Swimmers.

Abnormal fundamental movement patterns and upper-quarter dynamic balance are proposed mechanisms affecting athletic performance and injury risk. There are few studies investigating functional movement and closed-chain upper-extremity dynamic stability in swimmers. The purpose of this study was to determine differences in fundamental movement competency and closed-chain upper-extremity dynamic balance, using the Functional Movement Screen (FMS) and Upper-Quarter Y Balance Test (YBT-UQ), of high school (HS; n = 70) and collegiate (COL; n = 70) swimmers. Variables included the individual movement tests on the FMS and the average normalized reach (percent limb length [%LL]) for each direction, with the YBT-UQ. Statistical analysis was completed using a chi square for the independent test scores on the FMS while independent samples t-test to examine performance on the YBT-UQ (p ≤ 0.05). HS swimmers exhibited a statistically significant greater percentage of below average performance (score of 0 or 1) on the following FMS tests: lunge (HS: 22.9%, COL: 4.3%), hurdle step (HS: 31.4%, COL: 7.1%), and push-up (HS: 61.4%, COL: 31.4%). Furthermore, COL males performed worse in the lunge (male: 9%, female: 0%), whereas COL females had poorer efficiency in the push-up (male: 17.6%, female: 44%). Significant effects of competition level and sex were observed in YBT-UQ medial reach (HS: female 92.06, male 101.63; COL: female 101.3, male 101.5% LL). Individual fundamental movement patterns that involved lumbopelvic neuromuscular control differed between HS and COL swimmers. General upper-extremity dynamic balance differed between competition levels. These data may be helpful in understanding injury and performance-based normative data for participation and return to swimming.

Difference in Functional Performance on the Upper-Quarter Y-Balance Test Between High School Baseball Players and Wrestlers.

CONTEXT: The Upper Quarter Y-Balance Test (YBT-UQ) is a unique movement test where individuals perform at the limits of their stability, requiring the coordination of balance, proprioception, range of motion, and stabilization. It is not yet clear if performance on the YBT-UQ differs between sports with dissimilar emphasis on upper-extremity performance. OBJECTIVE: To compare performance on the YBT-UQ between wrestlers, whose sport requires some degree of closed-chain activity, and baseball players, whose sport is primarily open kinetic chain in nature. DESIGN: Cross-sectional. SETTING: High school preparticipation physical assessment. PARTICIPANTS: 24 healthy high school male wrestlers (mean age 16.12 ± 1.24 y) and 24 healthy high school male baseball players (mean age 15.79 ± 1.25 y). INTERVENTIONS: All subjects performed the YBT-UQ, which requires reaching in 3 directions while maintaining a push-up position. MAIN OUTCOME MEASURES: The variables of interest include the maximum reach in each direction, as well as the composite score. In addition, asymmetries between limbs for each reach direction were compared. RESULTS: Wrestlers performed significantly better than baseball players in the medial direction, inferolateral direction, and in composite scores. In the medial direction, wrestlers exhibited greater scores (P < .01) on both left and right limbs, 10.5 ± 10.2%LL and 9.95 ± 10.2%LL, respectively. Significant differences (P < .01) were also observed in the inferolateral direction, with a difference of 11.3 ± 12.0%LL on the left and 8.7 ± 11.0%LL on the right. Composite scores were higher (P < .01) for the wrestlers, with a difference of 7.0% on the left and 7.1% on the right. CONCLUSIONS: This study suggests that wrestlers perform better on the YBT-UQ than baseball players. The findings may suggest sport-specific normative data for the YBT-UQ in high school athletes.

Lower Extremity Movement Differences Persist After Anterior Cruciate Ligament Reconstruction and When Returning to Sports.

OBJECTIVE: To examine how landing mechanics change in patients after anterior cruciate ligament reconstruction (ACL-R) between 6 months and 12 months after surgery. DESIGN: Case-series. SETTING: Laboratory. PARTICIPANTS: Fifteen adolescent patients after ACL-R participated. INTERVENTIONS: Lower extremity three-dimensional motion analysis was conducted during a bilateral stop jump task in patients at 6 and 12 months after ACL-R. Joint kinematic and kinetic data, in addition to ground reaction forces, were collected at each time point. MAIN OUTCOME MEASURES: During the stop jump landing, the peak joint moments and the initial and peak joint motion at the ankle, knee, and hip were examined. The peak vertical ground reaction force was also examined. RESULTS: Interactions were observed for both the peak knee (P = 0.03) and hip extension moment (P = 0.07). However, only the hip extension moment was symmetrical level at 12 months. Statistically significant (P < 0.05) side-to-side differences existed for the ankle angle at initial contact, peak plantarflexion moment, peak hip flexion angle, and peak impact vertical ground reaction force independent of time. CONCLUSIONS: The findings of this study suggest that sagittal plane moments at the knee and hip demonstrate an increase in symmetry between 6 months and 1 year after ACL-R surgery, however, symmetry of the knee extension moment is not established by 12 months after surgery. The lack of change in the variables across time was unexpected. As a result, it is inappropriate to expect a change in landing mechanics solely as a result of time alone after discharge from rehabilitation.

Gender Differences in Plantar Loading During an Unanticipated Side Cut on FieldTurf.

OBJECTIVE: To determine whether force-time integral (FTI) and maximum force (MF) are significantly different between genders when performing an unanticipated side cut on FieldTurf. DESIGN: Thirty-two collegiate athletes (16 men and 16 women) completed 12 unanticipated cutting trials, while plantar pressure data were recorded using Pedar-X insoles. SETTING: Controlled Laboratory Study. PARTICIPANTS: Division I cleated sport athletes with no previous foot and ankle surgery, no history of lower extremity injury in the past 6 months, and no history of metatarsal stress fracture. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Maximum force and the FTI in the total foot, medial midfoot (MMF), lateral midfoot (LMF), medial forefoot (MFF), middle forefoot (MiddFF), and the lateral forefoot (LFF). RESULTS: Males had a greater FTI beneath the entire foot (TF) (P < 0.001). Females had a significantly higher MF beneath the LMF (P = 0.001), MiddFF (P < 0.001), and LFF (P = 0.001). Males had a significantly greater MF beneath the MMF (P = 0.003) and greater FTI beneath the MMF (P < 0.001) and MFF (P = 0.002). CONCLUSIONS: Significant differences in plantar loading exist between genders with males demonstrating increased loading beneath the TF in comparison with females. Females had overall greater loading on the lateral column, whereas males had greater loading on the medial column of the foot. CLINICAL RELEVANCE: The results of this study indicate that plantar loading is different between genders; therefore, altering cleated footwear to be gender specific may result in more optimal foot loading patterns. Optimizing cleated shoe design could decrease the risk for metatarsal stress fractures.

Functional Movement Competency and Dynamic Balance After Anterior Cruciate Ligament Reconstruction in Adolescent Patients.

BACKGROUND: Adolescent patients undergoing anterior cruciate ligament (ACL) reconstruction may not adequately recover safe movement patterns before returning to sport participation. The aims of this study were to assess functional movement and dynamic balance 9 months after primary ACL reconstruction in adolescent patients, and to assess for any maturity-specific differences that may guide rehabilitation strategies. METHODS: A series of 39 adolescent patients who underwent primary, anatomic, transphyseal ACL reconstruction using hamstrings autograft from October 2009 to January 2013 were identified from a research database: 17 skeletally immature (SI) patients (mean age 13.6±1.6 y) and 22 skeletally mature (SM) patients (mean age 16.6±1.2 y). An adult reference population of 16 primary ACL reconstruction patients (mean age 27.4±4.0 y) was also identified. All patients followed a standardized operative and rehabilitation protocol. The 3 patient groups were compared 9 months postoperatively using the Functional Movement Screen (FMS) to assess movement competency and the Lower Quarter Y-Balance Test (LQYBT) to assess single-limb dynamic balance. RESULTS: Nine months postoperatively, the FMS scores for all 3 groups indicated an increased risk for lower extremity injury (total score ≤14). With respect to specific movement patterns, the SI group displayed inferior active straight leg raise score (P=0.006) despite a lower incidence of pain with this movement. With the LQYBT, there was no significant difference in mean anterior (P=0.987), posterolateral (P=0.349), or posteromedial (P=0.870) reach asymmetry between the 3 groups; however, the adolescent groups demonstrated wider ranges of anterior reach asymmetry than the adult group indicating an increased risk for injury. CONCLUSIONS: Adolescent patients undergoing primary ACL reconstruction do not consistently recover adequate functional movement patterns by 9 months postoperatively to permit a safe return to sport. We have identified unique functional movement deficits in SI and SM adolescents, which highlight the need for maturity-specific rehabilitation strategies for adolescent patients undergoing ACL reconstruction. LEVEL OF EVIDENCE: Level IV­retrospective cohort

Are Range of Motion Measurements Needed When Calculating the Harris Hip Score?

BACKGROUND: Often the patient-reported outcome (PRO) component of the Harris Hip Score (HHS) is completed, but the physician-assessed range of motion (ROM) component is not. The PRO component only is called a modified Harris Hip Score (mHHS). The purpose of this study was to determine if a statistically significant or clinically meaningful difference existed when calculating the HHS with and without the physician-reported ROM portion. METHODS: Included patients had complete HHS data (both physician and PRO components). Surgical procedure (primary or revision) was recorded for each subject. American Society of Anesthesiologists score was divided into low and high groups. Body mass index was divided into 4 categories. The study used a repeated measures design. RESULTS: Data on 483 patients were collected between 12 and 60 months postoperatively (mean follow-up: 32.5 months, mean age: 55.9 ± 13.5 years). A mean difference of 4 points existed between the 2 groups: HHS group average score was 84.56 ± 13.18, and mHHS group average score was 88.74 ± 13.77. American Society of Anesthesiologists score, body mass index, and surgical type demonstrated a significant interaction with the HHS calculation method (P < .001). Primary total joint patients demonstrated a greater difference between the 2 scoring methods compared with revision patients. CONCLUSION: No clinically meaningful difference in outcomes was found between the mHHS and the HHS. The calculation of the HHS is dependent on the inclusion of the ROM measurement. However, the small point difference between the HHS and mHHS indicates that the mHHS is still useful as an accurate determinant of patient clinical outcome, and ROM assessment is not essential.

Reliability and Validity of a Novel Approach to Measure Hip Rotation.

CONTEXT: Currently, hip-rotation range of motion (ROM) is clinically measured in an open kinetic chain in either seated or prone position using passive or active ROM. However, during activities of daily living and during sports participation the hip must be able to rotate in a loaded position, and there is no standard measurement for this. OBJECTIVE: To determine if a novel method for measuring hip rotation in weight bearing will result in good to very good reliability as demonstrated by an intraclass correlation coefficient (ICC) of >.80 and to investigate if weight-bearing hip measurements will result in significantly reduced hip ROM compared with non-weight-bearing methods. DESIGN: Repeated measures. SETTING: Outpatient sports physical therapy clinic. PARTICIPANTS: 20 healthy participants (10 men, 10 women) recruited for hip-rotation measurements. METHODS: Three trials of both internal and external rotation were measured in sitting, prone, and weight bearing. Two therapists independently measured each participant on the same day. The participants returned the following day to repeat the same measurements with the same 2 therapists. MAIN OUTCOME MEASURES: Degrees of hip internal and external rotation measured in prone, sitting, and loaded positions. RESULTS: In general, the measurement of hip ROM across the different conditions was reliable. The intrarater reliability was .67-.95, while interrater reliability was .59-.96. Interrater reliability was improved when values were averaged across the measures (.75-.97). ICCs for active loaded ROM were .67-.81, while interrater ICCs were .53-.87. In general, prone hip ROM was greater than supine and supine was greater than loaded. CONCLUSIONS: Loaded hip rotation can be measured in a clinical setting with moderate to good reliability. The rotation ROM of a loaded hip can be significantly decreased compared with unloaded motion.

What Risk Factors Are Associated With Musculoskeletal Injury in US Army Rangers? A Prospective Prognostic Study.

BACKGROUND: Musculoskeletal injury is the most common reason that soldiers are medically not ready to deploy. Understanding intrinsic risk factors that may place an elite soldier at risk of musculoskeletal injury may be beneficial in preventing musculoskeletal injury and maintaining operational military readiness. Findings from this population may also be useful as hypothesis-generating work for particular civilian settings such as law enforcement officers (SWAT teams), firefighters (smoke jumpers), or others in physically demanding professions. QUESTIONS/PURPOSES: The purposes of this study were (1) to examine whether using baseline measures of self-report and physical performance can identify musculoskeletal injury risk; and (2) to determine whether a combination of predictors would enhance the accuracy for determining future musculoskeletal injury risk in US Army Rangers. METHODS: Our study was a planned secondary analysis from a prospective cohort examining how baseline factors predict musculoskeletal injury. Baseline predictors associated with musculoskeletal injury were collected using surveys and physical performance measures. Survey data included demographic variables, injury history, and biopsychosocial questions. Physical performance measures included ankle dorsiflexion, Functional Movement Screen, lower and upper quarter Y-balance test, hop testing, pain provocation, and the Army Physical Fitness Test (consisting of a 2-mile run and 2 minutes of sit-ups and push-ups). A total of 320 Rangers were invited to enroll and 211 participated (66%). Occurrence of musculoskeletal injury was tracked for 1 year using monthly injury surveillance surveys, medical record reviews, and a query of the Department of Defense healthcare utilization database. Injury surveillance data were available on 100% of the subjects. Receiver operator characteristic curves and accuracy statistics were calculated to identify predictors of interest. A logistic regression equation was then calculated to find the most pertinent set of predictors. Of the 188 Rangers (age, 23.3 ± 3.7 years; body mass index, 26.0 ± 2.4 kg/m(2)) remaining in the cohort, 85 (45.2%) sustained a musculoskeletal injury of interest. RESULTS: Smoking, prior surgery, recurrent prior musculoskeletal injury, limited-duty days in the prior year for musculoskeletal injury, asymmetrical ankle dorsiflexion, pain with Functional Movement Screen clearing tests, and decreased performance on the 2-mile run and 2-minute sit-up test were associated with increased injury risk. Presenting with one or fewer predictors resulted in a sensitivity of 0.90 (95% confidence interval [CI], 0.83-0.95), and having three or more predictors resulted in a specificity of 0.98 (95% CI, 0.93-0.99). The combined factors that contribute to the final multivariable logistic regression equation yielded an odds ratio of 4.3 (95% CI, 2.0-9.2), relative risk of 1.9 (95% CI, 1.4-2.6), and an area under the curve of 0.64. CONCLUSIONS: Multiple factors (musculoskeletal injury history, smoking, pain provocation, movement tests, and lower scores on physical performance measures) were associated with individuals at risk for musculoskeletal injury. The summation of the number of risk factors produced a highly sensitive (one or less factor) and specific (three or more factors) model that could potentially be used to effectively identify and intervene in those persons with elevated risk for musculoskeletal injury. Future research should establish if screening and intervening can improve musculoskeletal health and if our findings among US Army Rangers translate to other occupations or athletes. LEVEL OF EVIDENCE: Level II, prognostic study.

Unipedal balance is affected by lower extremity joint arthroplasty procedure 1 year following surgery.

Lower Extremity Joint Arthroplasty (LEJA) surgery is an effective way to alleviate painful osteoarthritis. Unfortunately, these surgeries do not normalize the loading asymmetry during the single leg stance phase of gait. Therefore, we examined single leg balance in 234 TJA patients (75 hips, 65 knees, 94 ankles) approximately 12 months following surgery. Patients passed if they maintained single leg balance for 10s with their eyes open. Patients one year following total hip arthroplasty (THA-63%) and total knee arthroplasty (TKA-69%) had similar pass rates compared to a total ankle arthroplasty (TAA-9%). Patients following THA and TKA exhibit better unilateral balance in comparison with TAA patients. It may be beneficial to include a rigorous proprioception and balance training program in TAA patients to optimize functional outcomes.

A single set of biomechanical variables cannot predict jump performance across various jumping tasks.

Vertical jump performance is related to high-level function in athletics. The purpose of this study was to determine whether a single set of biomechanical variables exist that can predict vertical jump height during multiple jumping strategies: single foot jump, drop jump, and countermovement jump. Three-dimensional mechanics were collected during the 3 different jumping tasks in 50 recreational male athletes. Three successful trials were analyzed for each jump type. Testing order was randomized to minimize fatigue effects, and the dominant limb was used for analysis. All discrete variables were correlated to jump height and the 10 variables that had the strongest correlation were inserted into a linear regression model to identify what variables predicted maximum jump height. No single set of variables that predicted jump height existed across all 3 jumping tasks. One foot jump height was predicted by peak knee power, peak hip extension moment, peak knee extension velocity, and the percentage of the trial when peak knee flexion velocity occurred (r = 0.58). Countermovement jump height was predicted by peak hip power, ankle range of motion, and knee range of motion (r = 0.65). Drop jump height was predicted by the peak vertical ground reaction force and the percentage of the trial when the peak hip velocity occurred (r = 0.37). A single set of variables was not identified that could predict jump performance across different types of jumping tasks; therefore, additional interventional investigations are needed to better understand how to alter and improve jump performance.

Use of Liposomal Bupivacaine Instead of an Epidural Can Improve Outcomes Following Total Knee Arthroplasty.

The purpose of this study was to compare periarticular injection of liposomal bupivacaine (LB) to epidural analgesia as part of multimodal pain management strategy for total knee arthroplasty (TKA). A retrospective review of 50 patients undergoing TKA compared 25 patients who received LB to 25 patients who received an epidural. After postoperative day 1, patients who received LB exhibited significantly lower (p < .001) pain scores than those who received an epidural. Patients who received LB also had a significantly shorter length of hospital stay (p < .0001), greater range of motion on postoperative day 1, and walked significantly farther (p < .001) on postoperative day 1. LB appears to provide effective pain control leading to shorter hospital stays and improved early physical function compared with standard pain management with an epidural.

Percent body fat more associated with perioperative risks after total joint arthroplasty than body mass index.

Understanding the impact of obesity on elective total joint arthroplasty (TJA) remains critical. Perioperative outcomes were reviewed in 316 patients undergoing primary TJA. Higher percent body fat (PBF) was associated with postoperative blood transfusion, increased hospital length of stay (LOS) >3 days, and discharge to an extended care facility while no significant differences existed for BMI. Additionally, PBF of 43.5 was associated with a 2.4× greater likelihood of blood transfusion, PBF of 36.5 with a 1.9× greater likelihood for LOS >3 days, and PBF of 36.0 with a 1.4× greater likelihood for discharge to an extended care facility. PBF may be a more effective measure than BMI to use in screening for perioperative risks and acute outcomes associated with obese total joint patients.

Prediction of injury by limited and asymmetrical fundamental movement patterns in american football players.

CONTEXT: Previous injury is the strongest risk factor for future injury in sports. It has been proposed that motor-control changes such as movement limitation and asymmetry associated with injury and pain may be perpetuated as part of an individual's movement strategy. Motor control of fundamental 1-×-body-weight tasks can reliably and efficiently be measured in the field. OBJECTIVE: To determine whether the motor control of fundamental movement patterns and pattern asymmetry have a relationship with time-loss injury over the course of the preseason in professional football. DESIGN: Injury-risk study. SETTING: American professional football facilities. PARTICIPANTS: 238 American professional football players. INTERVENTION: To measure the motor control of 1-×-body-weight fundamental movement patterns, Functional Movement Screen scores were obtained before the start of training camp. The previously established cutoff score of ≤14 and the presence of any asymmetries on the FMS were examined using relative risk to determine if a relationship exists with time-loss injury. MAIN OUTCOME MEASURE: Time-loss musculoskeletal injury defined as any time loss from practice or competition due to musculoskeletal injury. RESULTS: Players who scored ≤14 exhibited a relative risk of 1.87 (CI95 1.202.96). Similarly, players with at least 1 asymmetry displayed a relative risk of 1.80 (CI95 1.112.74). The combination of scoring below the threshold and exhibiting a movement asymmetry was highly specific for injury, with a specificity of .87 (CI95 .84.90). CONCLUSION: The results of this study suggest that fundamental movement patterns and pattern asymmetry are identifiable risk factors for time-loss injury during the preseason in professional football players.

Gender differences in landing mechanics vary depending on the type of landing.

OBJECTIVE: Men and women exhibit different movement patterns, which are thought to contribute to the increased incidence of anterior cruciate ligament injuries in females. Although gender differences have been observed in movement, few studies have examined gender differences during different types of landings. DESIGN: Prospective gender comparison study. SETTING: Controlled laboratory study. PATIENTS: Fourteen male and 14 female recreational soccer players were recruited for the study. All subjects performed a soccer-specific jump heading activity to examine differences in landing mechanics before and after heading the soccer ball. Subjects began the task by performing a forward jump onto 2 force platforms (landing 1) and conducting a countermovement before jumping up to head a soccer ball that was hanging above the force platform before, then landing back on the force platforms (landing 2). MAIN OUTCOME MEASURES: A 2-way analysis of variance (gender × landing) was performed to examine the interaction between gender and different types of landings on sagittal plane joint mechanics. RESULTS: Significant interactions existed for the peak hip extension moment and vertical ground reaction force where the male players exhibited increased values during the second landing compared with the female players. Males exhibited greater peak plantarflexion and knee extension moments, but decreased peak hip flexion. Main effects for landing exhibited lower kinematic and larger kinetic values except for the peak plantarflexion moment. CONCLUSIONS: Female and male players appear to land differently depending on the type of landing. Therefore, specificity of landing type may be important to consider when screening for injury risk factors. CLINICAL RELEVANCE: This study examines the differences between genders during 2 different landing tasks and demonstrates the importance of considering the jumping task when screening individuals for injury risk factors.

Does surgical approach during total hip arthroplasty alter gait recovery during the first year following surgery?

Multiple surgical approaches exist for total hip arthroplasty (THA). Each approach has risks and benefits in regard to complications and changes in postoperative gait. This study examined the effect of three surgical approaches on postoperative gait mechanics. Thirty patients completed a self-selected speed level walking gait assessment preoperatively, 6 weeks, and 1 year after surgery. We found no difference between approaches 1 year following surgery for any study variable. Several differences existed between time points independent of surgical approach. Significant improvement was found in sagittal and frontal plane hip ROM, peak hip extension and adduction angle and moment, the functional measures, walking speed, and the Harris Hip Score. This study suggests that postoperative gait changes are similar for the three analyzed surgical approaches.

Difference in peak weight transfer and timing based on golf handicap.

Weight shift during the golf swing has been a topic of discussion among golf professionals; however, it is still unclear how weight shift varies in golfers of different performance levels. The main purpose of this study was to examine the following: (a) the changes in the peak ground reaction forces (GRF) and the timing of these events between high (HHCP) and low handicap (LHCP) golfers and (b) the differences between the leading and trailing legs. Twenty-eight male golfers were recruited and divided based on having an LHCP < 9 or HHCP > 9. Three-dimensional GRF peaks and the timing of the peaks were recorded bilaterally during a golf swing. The golf swing was divided into different phases: (a) address to the top of the backswing, (b) top of the backswing to ball contact, and (c) ball contact to the end of follow through. Repeated measures analyses of variance (α = 0.05) were completed for each study variable: the magnitude and the timing of peak vertical GRF, peak lateral GRF, and peak medial GRF (α = 0.05). The LHCP group had a greater transfer of vertical force from the trailing foot to the leading foot in phase 2 than the HHCP group. The LHCP group also demonstrated earlier timing of peak vertical force throughout the golf swing than the HHCP group. The LHCP and HHCP groups demonstrated different magnitudes of peak lateral force. The LHCP group had an earlier timing of peak lateral GRF in phase 2 and earlier timing of peak medial GRF in phases 1 and 2 than the HHCP group. In general, LHCP golfers demonstrated greater and earlier force generation than HHCP golfers. It may be relevant to consider both the magnitude of the forces and the timing of these events during golf-specific training to improve performance. These data reveal weight shifting differences that can be addressed by teaching professionals to help their students better understand weight transfer during the golf swing to optimize performance.

A Field-expedient Arm Care Screening Tool Can Identify Musculoskeletal Risk Factors in Baseball Players.

BACKGROUND: Preseason movement screening can identify modifiable risk factors, deterioration of function, and potential for injury in baseball players. Limited resources and time prevent high school baseball coaches from performing movement screens on their players. HYPOTHESIS: The arm care screen (ACS) will be highly sensitive to detecting musculoskeletal risk factors. STUDY DESIGN: Cross-sectional. LEVEL OF EVIDENCE: Level 3. METHODS: A total of 150 baseball players were independently scored on the ACS electronically by reviewing a video recording of each player's screening performance. Discriminability of the ACS was determined with a 2 × 2 contingency table dichotomizing musculoskeletal risk factors as present or absent based on a predetermined cutoff value and those who passed or failed the corresponding ACS subtest. RESULTS: High sensitivity was observed on the reciprocal shoulder mobility (0.89; 95% CI 0.81-0.94), 90/90 total body rotation (0.86; 95% CI 0.79-0.92), and lower body diagonal reach (0.85; 95% CI 0.78-0.91) tests of the ACS suggesting sufficient ability to identify musculoskeletal impairments and risk factors. CONCLUSION: The ACS is a simplistic screening tool that the coach can administer to discriminate between youth, high school, and college-level baseball players who possess musculoskeletal risk factors. The ACS subtests demonstrated high sensitivity for correctly identifying musculoskeletal risk factors common in baseball players and can be useful as a screening tool for baseball coaches developing arm care exercise programs. CLINICAL RELEVANCE: A field-expedient screen could provide coaches the ability to identify musculoskeletal risk factors that need to be addressed to minimize injury risk factors in a time-efficient manner.