Marker-Based Versus IMU-Based Kinematics for Estimates of Lumbar Spine Loads Using a Full-Body Musculoskeletal Model.

Musculoskeletal modeling, typically implemented using marker-based systems in laboratory environments, is commonly used for noninvasive estimations of loads. Inertial measurement units (IMUs) have become an alternative for the evaluation of kinematics. However, estimates of spine joint contact forces using IMUs have yet to be thoroughly evaluated. Dynamics tasks and static postures from activities of daily living were captured on 11 healthy subjects using both systems simultaneously. Spine kinematics obtained from IMU- and marker-based systems and L4-L5 joint contact forces were compared. Lateral bending resulted in a weak agreement with significant differences between the 2 systems (P = .02, average root mean-squared error = 4.81), whereas flexion-extension and axial rotation exhibited the highest agreement with no significant differences (P < .05, average root mean-squared error = 5.51 and P < .31, average root mean-squared error = 5.08, respectively). All tasks showed excellent correlations (R2 = .76-.99) in estimated loads between systems. Differences in predicted loads at the L4-L5 were only observed during flexion-extension (1041 N vs 947 N, P = .0004) and walking with weights (814 N vs 727 N, P = .004). Different joint reaction force outcomes were obtained in 2 of the 8 tasks between systems, suggesting that IMUs can be robust tools allowing for convenient and less expensive evaluations and for longitudinal assessments inside and outside the laboratory setting.

Intrasession and Intersession Reliability of Isometric Trunk and Hip Strength Measurements Using the Portable Tension Dynamometer.

CONTEXT: The trunk/pelvis is an important link between the upper- and lower-extremities. Therefore, assessing strength of the trunk and hip muscles that control the segments is clinically meaningful. While an isokinetic dynamometer can be used to measure trunk strength, the equipment is expensive and not portable. OBJECTIVE: To test the reliability of simple trunk and hip strength measures that utilize a bar, straps, and a portable tension dynamometer. DESIGN: Test-retest reliability study. SETTING: Biomechanics research laboratory. Patients (or Other Participants): Twenty college-age individuals (10 males/10 females, age = 20.9 [3.7] y) participated. INTERVENTION(S): The participants attended 2 testing sessions, 1 week apart. The participants' trunk-flexion, rotation, and hip abduction strength were measured at each session. MAIN OUTCOME MEASURES: Peak trunk flexion, rotation, and hip abduction forces were normalized to the participant's body weight (BW). In addition, hip-abduction torque was calculated by multiplying the force times the leg length and normalized to BW. The trial data from both sessions were used to calculate the intrasession reliability, and the averages from the 2 sessions were used to calculate the intersession reliability. Intraclass correlation coefficients, SEM, and minimal detectable change were calculated to evaluate reliability of measures. RESULTS: The intrasession intraclass correlation coefficients (SEM) for trunk flexion, rotation, hip abduction, and hip abduction torque were .837 (5.2% BW), .978 (1.3% BW), .955 (1.0% BW), and .969 (5.8 N·m/BW), respectively. The intersession reliability for trunk flexion, rotation, hip abduction, and hip abduction torque were .871 (4.3% BW), .801 (3.8% BW), .894 (1.5% BW), and .968 (5.9 N·m/BW), respectively. CONCLUSIONS: The measures of trunk and hip abduction strength are highly repeatable within a session. The reliability of the measures between sessions was also good/excellent with relatively small SEM and minimal detectable change. The tests described in this study can be used to assess changes in trunk/hip strength over time.

The Relationship Between the Push Off Ground Reaction Force and Ball Speed in High School Baseball Pitchers.

Oyama, S and Myers, JB. The relationship between the push off ground reaction force and ball speed in high school baseball pitchers. J Strength Cond Res 32(5): 1324-1328, 2018-Baseball pitching is a sequential movement that requires transfer of momentum from the lower extremity to the throwing arm. Therefore, the ground reaction force (GRF) during push off is suggested to play a role in production of ball speed. The purpose of this study was to investigate the correlation between GRF characteristics during push off and ball speed in high school baseball pitchers. A total of 52 pitchers performed fast pitches from an indoor pitching mound. A force plate embedded in an indoor mound was used to capture the push off GRF. The GRF characteristics (peak anterior, vertical, and resultant forces, vertical and resultant forces at the time of peak anterior GRF, and impulse produced by the anterior GRF) from the 3 fastest strike pitches from each pitcher were used for analyses. Spearman's rank correlation coefficients were used to describe the relationships between ball speed and the GRF characteristics. Ball speed was only weakly correlated with peak resultant force (ρ = 0.32, p = 0.02) and vertical (ρ = 0.45, p < 0.001) and resultant (ρ = 0.42, p = 0.002) forces at the time of peak anterior force. The ball speed was not correlated with other variables. The correlation between ball speed and push off force in high school pitchers was weak, especially when compared with what was reported for adult pitchers in other studies. Unlike for adult pitchers, higher push off force is only weakly correlated with ball velocity in high school pitchers, which suggests that training to better use body momentum may help high school pitchers improve ball speed.

Trunk Muscle Function Deficit in Youth Baseball Pitchers With Excessive Contralateral Trunk Tilt During Pitching.

OBJECTIVE: Pitching technique is one of many factors that affect injury risk. Exhibiting excessive contralateral trunk tilt (CLT) during pitching has been linked to higher ball speed but also to increased joint loading. Deficit in trunk muscle strength has been suggested as an underlying cause of this movement pattern. The purpose of the study was to compare trunk muscle strength between youth baseball pitchers with varying degree of CLT during pitching. DESIGN: Cross-sectional study. SETTING: Baseball practice fields. PARTICIPANTS: Twenty-eight youth baseball pitchers. INDEPENDENT VARIABLES: Pitching technique was captured using a video camera. Based on the 2-dimensional trunk contralateral flexion angle, pitchers were categorized into low (<15 degrees), moderate (15-30 degrees), or high (>30 degrees) CLT groups. MAIN OUTCOME MEASURES: Maximum isometric strength tests for trunk flexion, extension, and bilateral rotation, measured using a dynamometer. RESULTS: The pitchers with high CLT (n = 10) had longer pitching experience (P = 0.014), produced higher ball speed (P = 0.003) compared with the pitchers with moderate (n = 10) and low (n = 8) CLT, but demonstrated greater asymmetry in trunk rotation strength (relative weakness in rotation strength toward dominant side) compared with the pitchers with low CLT (P = 0.015). CONCLUSIONS: Excessive CLT may be a strategy that young pitchers learn to achieve higher ball velocity but also may be associated with imbalance between the oblique muscles on dominant and nondominant side, which may be acquired from repetitive pitching. Strengthening and emphasizing the use of dominant side oblique muscles may keep pitchers from leaning excessively during pitching and thus decrease joint loading.

Preseason screening of shoulder range of motion and humeral retrotorsion does not predict injury in high school baseball players.

BACKGROUND: Shoulder and elbow injuries are commonplace in high school baseball. Although altered shoulder range of motion (ROM) and humeral retrotorsion angles have been associated with injuries, the efficacy of preseason screening of these characteristics remains controversial. METHODS: We conducted preseason screenings for shoulder internal and external rotation ROM and humeral retrotorsion on 832 high school baseball players and tracked their exposure and incidence on throwing-related shoulder and elbow injuries during a subsequent season. Poisson regression with robust error variance was used to determine whether preseason screening could identify injury risk in baseball players and whether the injury risk was higher for pitchers compared with players who do not pitch. RESULTS: Shoulder rotation ROM or humeral retrotorsion at preseason did not predict the risk of throwing-related upper extremity injury (P = .15-.89). Injury risk was 3.84 higher for baseball players who pitched compared with those who did not (95% confidence interval, 1.72-8.56; P = .001). DISCUSSION: Preseason measures of shoulder ROM and humeral retrotorsion may not be effective in identifying players who are at increased injury risk. Because shoulder ROM is a measure that fluctuates under a variety of influences, future study should investigate whether taking multiple measurements during a season can identify at-risk players. The usefulness of preseason screening may also depend on rigor of participation in sports. Future studies should investigate how preseason shoulder characteristics and participation factors (ie, pitch count and frequency, competitive level, pitching in multiple leagues) interact to predict injury risk in baseball players.

Reliability and Validity of Quantitative Video Analysis of Baseball Pitching Motion.

Video recordings are used to quantitatively analyze pitchers' techniques. However, reliability and validity of such analysis is unknown. The purpose of the study was to investigate the reliability and validity of joint and segment angles identified during a pitching motion using video analysis. Thirty high school baseball pitchers participated. The pitching motion was captured using 2 high-speed video cameras and a motion capture system. Two raters reviewed the videos to digitize the body segments to calculate 2-dimensional angles. The corresponding 3-dimensional angles were calculated from the motion capture data. Intrarater reliability, interrater reliability, and validity of the 2-dimensional angles were determined. The intrarater and interrater reliability of the 2-dimensional angles were high for most variables. The trunk contralateral flexion at maximum external rotation was the only variable with high validity. Trunk contralateral flexion at ball release, trunk forward flexion at foot contact and ball release, shoulder elevation angle at foot contact, and maximum shoulder external rotation had moderate validity. Two-dimensional angles at the shoulder, elbow, and trunk could be measured with high reliability. However, the angles are not necessarily anatomically correct, and thus use of quantitative video analysis should be limited to angles that can be measured with good validity.

Evaluation of upper body kinematics and muscle activity during milking attachment task.

The objective of the study was to evaluate the effects of udder height on upper body kinematics and muscle activity during a simulated attachment task in a parallel parlor set up, and the effects of udder access method (back or side) on the task biomechanics. Twenty males performed the task under conditions that simulated three udder heights and two udder access methods. The muscular load and kinematics during the task confirmed that milking is a physically demanding task. Trunk flexion angle increased with decreasing udder height, and the erector spinae activation was higher when the udder was below shoulder height compared to at or above. Compared to accessing the udder from side of the cow (herringbone parlor style), accessing from behind (Parallel parlor style) was associated with lower trunk flexion, greater shoulder horizontal adduction, lower shoulder elevation, and greater anterior deltoid activation. Milking in herringbone parlor style and with the udder at or above shoulder level may help reduce strain on the trunk/neck.

Accuracy and repeatability of an inertial measurement unit system for field-based occupational studies.

The accuracy and repeatability of an inertial measurement unit (IMU) system for directly measuring trunk angular displacement and upper arm elevation were evaluated over eight hours (i) in comparison to a gold standard, optical motion capture (OMC) system in a laboratory setting, and (ii) during a field-based assessment of dairy parlour work. Sample-to-sample root mean square differences between the IMU and OMC system ranged from 4.1° to 6.6° for the trunk and 7.2°-12.1° for the upper arm depending on the processing method. Estimates of mean angular displacement and angular displacement variation (difference between the 90th and 10th percentiles of angular displacement) were observed to change <4.5° on average in the laboratory and <1.5° on average in the field per eight hours of data collection. Results suggest the IMU system may serve as an acceptable instrument for directly measuring trunk and upper arm postures in field-based occupational exposure assessment studies with long sampling durations. Practitioner Summary: Few studies have evaluated inertial measurement unit (IMU) systems in the field or over long sampling durations. Results of this study indicate that the IMU system evaluated has reasonably good accuracy and repeatability for use in a field setting over a long sampling duration.

Tutorial: Lessons Learned for Behavior Analysts from Data Scientists.

Big data is a computing term used to refer to large and complex data sets, typically consisting of terabytes or more of diverse data that is produced rapidly. The analysis of such complex data sets requires advanced analysis techniques with the capacity to identify patterns and abstract meanings from the vast data. The field of data science combines computer science with mathematics/statistics and leverages artificial intelligence, in particular machine learning, to analyze big data. This field holds great promise for behavior analysis, where both clinical and research studies produce large volumes of diverse data at a rapid pace (i.e., big data). This article presents basic lessons for the behavior analytic researchers and clinicians regarding integration of data science into the field of behavior analysis. We provide guidance on how to collect, protect, and process the data, while highlighting the importance of collaborating with data scientists to select a proper machine learning model that aligns with the project goals and develop models with input from human experts. We hope this serves as a guide to support the behavior analysts interested in the field of data science to advance their practice or research, and helps them avoid some common pitfalls.

The effects of sleep quality and sleep quantity on concussion baseline assessment.

OBJECTIVE: Proper concussion assessment is imperative for properly caring for athletes who sustain traumatic brain injuries. Decreased sleep quality and sleep quantity affect cognition and may threaten the validity of clinical measures often used as a part of the concussion assessment. The purpose of this study was to determine if sleep quality or sleep quantity affects performance on clinical measures of concussion. DESIGN: Prospective cohort design. SETTING: Clinical research center. PARTICIPANTS: One hundred fifty-five college student-athletes (57 females, 98 males; age = 18.8 ± 0.8 years; mass = 78.4 ± 19.6 kg; height = 177.4 ± 12.3 cm). INTERVENTIONS: We performed preseason baseline testing by using a well-accepted and multifaceted protocol inclusive of neurocognition, balance performance, and symptom reporting. Information related to sleep quality and sleep quantity was also collected during preseason baseline testing. MAIN OUTCOME MEASURES: The CNS Vital Signs battery (computerized neurocognitive test), Sensory Organization Test (computerized dynamic posturography), and a Graded Symptom Checklist (symptom evaluation) were used. RESULTS: Subjects with a low sleep quantity the night before baseline reported both a greater number of symptoms and higher total symptom severity score. No clinically significant effects for sleep quality were observed. CONCLUSIONS: Sleep-deprived athletes reporting for baseline testing should be rescheduled for testing after a normal night's sleep.

Scapular dysfunction in high school baseball players sustaining throwing-related upper extremity injury: a prospective study.

HYPOTHESIS AND BACKGROUND: Though commonly suggested as an injury risk factor, scapular dysfunction has not been established as a prospective cause of throwing-related upper extremity injury in baseball players. The purpose is to determine whether scapular dysfunction identified during preseason screening is predictive of increased risk of throwing-related shoulder and elbow injuries in high school baseball players. MATERIALS AND METHODS: The presence or absence of scapular dysfunction was obtained prospectively during preseason screenings in 246 high school baseball players over the 2010 and 2011 seasons. Exposure and injury surveillance data were then obtained weekly over the course of each season to determine whether scapular dysfunction was predictive of subsequent throwing-related upper extremities sustained. RESULTS: There were 12 throwing-related upper extremity injuries sustained in the 246 participants, yielding an injury rate of 1.0 per 1,000 athlete exposures. There were no significant differences in injury rates between the participants with normal scapular function versus subtle scapular dysfunction (P = .62), normal scapular function versus obvious scapular dysfunction (P = .26), or subtle versus obvious scapular dysfunction (P = .45). CONCLUSION: This study showed that scapular dysfunction identified during preseason screenings is not associated with subsequent throwing-related upper extremity injury.

Intracompartmental pressure in lower leg muscles and tibial nerve in healthy volunteers correlate to the stiffness measured using shear wave elastography.

BACKGROUND: Acute compartment syndrome in the lower leg is a painful condition characterized by an increase in intracompartmental pressure. To prevent misdiagnosis and delay in the recognition of the condition, which can lead to severe complications, continuous monitoring of intracompartmental pressure for at least 24 h. from the onset of initial symptoms has been recommended. The purpose of the current study was to establish shear wave elastography as a potential imaging biomarker for the observed increase in pressure in four compartments of the lower leg. METHODS: Eighteen healthy participants (9 males) without any injury in their leg muscles were recruited for the study after internal review board approval. Subjects were instructed to sit on a table and pressures at 60, 90, and 120 mmHg were applied using a pressure cuff placed above the proximal pole of the patella. Shear wave elastography-measured stiffness outcomes at baseline (0 mmHg) and at each cuff pressure level were obtained from the tibialis anterior, the peroneus longs, gastrocnemius medialis, and tibialis posterior muscles, as well as the tibial nerve. FINDINGS: Spearman's rank correlation coefficient showed strong correlations between shear wave elastography-measured stiffness from all four muscles and cuff pressure levels (r > 0.80, P < 0.05). Stiffness from the tibial nerve was also significantly correlated with cuff pressure levels (r > 0.99, P < 0.05). INTERPRETATION: Shear wave elastography imaging of lower leg muscles and nerve can be useful to non-invasively monitor intracompartmental pressure in patients suspected of acute compartment syndrome.

Scapulohumeral kinematic assessment of the forward kayak stroke in experienced whitewater kayakers.

By understanding the normal humeral and scapular kinematics during the kayak stroke, inferences about the relationship of kayaking technique and shoulder injury may be established. The purpose of this study was to describe scapular and humeral kinematics and to compare dominant versus nondominant symmetry in healthy whitewater kayakers performing the forward stroke. Twenty-five competent whitewater kayakers (mean age: 34.1 +/- 9.4 years, mean height: 1.768 +/- 0.093m, mean mass: 78.2 +/- 13.0 kg) underwent humeral and scapular kinematic assessment, using an electromagnetic tracking device, while kayaking on a kayak ergometer. Paired t-tests were used to determine symmetry. Scapular and humeral kinematic means and standard deviations at six time points during the kayak stroke were described. Scapular and humeral kinematics were shown to be similar upon bilateral comparison. The greatest potential for injury during the forward stroke may be at thrust paddle shaft vertical when the humerus is maximally elevated in internal rotation and adduction as subacromial structures may be mechanically impinged. The relationship between scapulohumeral kinematics related to injury at other time points are also described.

Reduced Injury Prevalence in Soccer Athletes Following GPS Guided Acclimatization.

GPS technology has been used to retrospectively correlate injury risk to changes in training load, however the use of GPS technology to plan and monitor training load over an acclimatization period to prevent musculoskeletal injury remains unexplored. This article reports the utility of GPS technology to help develop and monitor incremental increases in training load while transitioning from off-season to in season to reduce musculoskeletal injury. A series of daily minimum standards were established based on observed training loads in year 1 to gradually acclimate soccer athletes over a 5-week period prior to competition season in year 2. Daily check-ins with GPS data were used to ensure athletes met the standards to safely reach the expected training load of a competitive season. Following the 5-week GPS guided training program a lower overall prevalence of injury (Year 1: 92.6% (95%CI = 75.7-100) vs. Year 2: 55.2% (95%CI = 35.7-73.6)) (p = .002) and overall injury rate (Year 1: 8.1/1000 exposure hours (95%CI = 5.2-12) vs 4.6/1000 exposure hours (95%CI = 2.7-7.5) in year 2 (p = .08)) was observed. The observed reduction in injury prevalence and incidence demonstrates how GPS data can be used to proactively design and monitor preventative chronic training load acclimatization programs.

Comparison of 3 Airway Access Techniques During Suspected Spine Injury Management in American Football.

OBJECTIVE: To determine how head movement and time to access airway were affected by 3 emergency airway access techniques used in American football. DESIGN: Prospective counterbalanced design. SETTING: University research laboratory. PARTICIPANTS: Eighteen certified athletic trainers (ATCs) and 18 noncertified students (NCSs). INTERVENTIONS: Each participant performed 1 trial of each of the 3 after airway access techniques: quick release mechanism (QRM), cordless screwdriver (CSD), and pocket mask insertion (PMI). MAIN OUTCOME MEASURES: Time to task completion in seconds, head movement in each plane (sagittal, frontal, and transverse), maximum head movement in each plane, helmet movement in each plane, and maximum helmet movement in each plane. RESULTS: We observed a significant difference between all 3 techniques with respect to time required to achieve airway access (F2,68 = 263.88; P < 0.001). The PMI allowed for the quickest access followed by the QRM and CSD techniques, respectively. The PMI technique also resulted in significantly less head movement (F2,68 = 9.06; P = 0.001) and less maximum head movement (F2,68 = 13.84; P < 0.001) in the frontal plane compared with the QRM and CSD techniques. CONCLUSIONS: The PMI technique should be used to gain rapid airway access when managing a football athlete experiencing respiratory arrest in the presence of a suspected cervical spine injury. In the event the athlete does not present with respiratory arrest, the facemask may be removed carefully with a pocket mask ready. Medical professionals must be familiar with differences in equipment and the effects these may have on the management of the spine-injured athlete.

Comparison of 3 airway access techniques during suspected spine injury management in American football.

OBJECTIVE: To determine how head movement and time to access airway were affected by 3 emergency airway access techniques used in American football. DESIGN: Prospective counterbalanced design. SETTING: University research laboratory. PARTICIPANTS: Eighteen certified athletic trainers (ATCs) and 18 noncertified students (NCSs). INTERVENTIONS: Each participant performed 1 trial of each of the 3 after airway access techniques: quick release mechanism (QRM), cordless screwdriver (CSD), and pocket mask insertion (PMI). MAIN OUTCOME MEASURES: Time to task completion in seconds, head movement in each plane (sagittal, frontal, and transverse), maximum head movement in each plane, helmet movement in each plane, and maximum helmet movement in each plane. RESULTS: We observed a significant difference between all 3 techniques with respect to time required to achieve airway access (F(2,68) = 263.88; P < 0.001). The PMI allowed for the quickest access followed by the QRM and CSD techniques, respectively. The PMI technique also resulted in significantly less head movement (F(2,68) = 9.06; P = 0.001) and less maximum head movement (F(2,68) = 13.84; P < 0.001) in the frontal plane compared with the QRM and CSD techniques. CONCLUSIONS: The PMI technique should be used to gain rapid airway access when managing a football athlete experiencing respiratory arrest in the presence of a suspected cervical spine injury. In the event the athlete does not present with respiratory arrest, the facemask may be removed carefully with a pocket mask ready. Medical professionals must be familiar with differences in equipment and the effects these may have on the management of the spine-injured athlete.

Three-dimensional scapular and clavicular kinematics and scapular muscle activity during retraction exercises.

STUDY DESIGN: Controlled laboratory study. OBJECTIVES: To describe and compare scapular and clavicular kinematics and muscle activity during 6 retraction exercises in young healthy adults (mean +/- SD age, 23.2 +/- 2.4 years). BACKGROUND: Based on the association between shoulder injuries and scapular/clavicular movement, muscle activity during various exercises that target muscles surrounding the scapula have been investigated. However, the scapular and clavicular movements occurring during these exercises remain uninvestigated. Evaluation of the scapular and clavicular kinematics in addition to muscle activity provides additional information that allow clinicians to select exercises that best meet the patient's needs. METHODS: Three-dimensional scapular and clavicular kinematics and scapular muscle activity data were collected while the participants performed 6 scapular retraction exercises. One-way repeated-measures ANOVA and post hoc analyses were used to determine differences in scapular/clavicular kinematics and activation levels of the upper, middle, and lower trapezius and serratus anterior muscles occurring during the exercises. RESULTS: The general pattern of the kinematics observed during all retraction exercises was scapular external rotation, scapular upward rotation, scapular posterior tilting, clavicular retraction, and clavicular depression. However, the exercises resulted in varying amounts of scapular movement and muscle activity. CONCLUSION: Clinicians can select appropriate exercises for their patients based on their need to strengthen specific retractor muscles and to improve specific scapular and clavicular movement patterns, pre-existing conditions, and available range of motion.

Influence of humeral torsion on interpretation of posterior shoulder tightness measures in overhead athletes.

OBJECTIVE: To measure the influence of humeral torsion on interpretation of clinical indicators of posterior shoulder tightness in overhead athletes. DESIGN: Cross-sectional control group comparison. SETTING: A university-based sports medicine research laboratory. PARTICIPANTS: Twenty-nine healthy intercollegiate baseball players and 25 college-aged control individuals with no history of participation in overhead athletics were enrolled. INTERVENTION: In all participants, bilateral humeral rotation and humeral horizontal adduction variables were measured with a digital inclinometry. Bilateral humeral torsion was measured with ultrasonography. MAIN OUTCOME MEASURES: Group and limb comparisons were made for clinical indicators of posterior shoulder tightness (humeral rotation and horizontal adduction variables) and humeral torsion variables. The relationship between humeral torsion and clinical indicators of posterior shoulder tightness were established. RESULTS: The dominant limb of the baseball players demonstrated greater humeral torsion, and less internal rotation and total rotation range of motion, compared with control participants and the nondominant limb in both groups. Once corrected for torsion, no group or limb differences in internal rotation were present. Statistically significant relationships existed between the amount of humeral torsion and measures of posterior shoulder tightness. CONCLUSIONS: Although limb differences in clinical indicators of posterior tightness exist in healthy overhead athletes, these measures appear to be influenced by humeral torsion rather than soft tissue tightness. Once torsion is accounted for, the limb differences observed clinically were minimal in healthy overhead athletes. When possible, accounting for humeral torsion when interpreting clinical measures of posterior shoulder tightness may aid in treatment decisions.

Clinical medication review type III of polypharmacy reduced unplanned hospitalizations in older adults: A meta-analysis of randomized clinical trials.

AIM: To analyze the impact of clinical medication reviews (CMR) on reducing unplanned hospitalizations owing to polypharmacy among older adults using an intervention. METHODS: Our meta-analysis complied with PRISMA guidelines. The literature review comprised a search for articles published between January 1972 and March 2017 on MEDLINE and Google Scholar. We identified randomized controlled trials focusing on CMR that evaluated unplanned hospitalization and re-hospitalization among older adults as a primary outcome. The keywords used were "CMR" or "medication review" in their titles, and the phrases "elderly" or "older adults" or "geriatric" and "polypharmacy." The randomized controlled trials selected were divided according to the three types of CMR to analyze the characteristics of each review. RESULTS: We included nine randomized controlled trials that examined the impact of CMR of polypharmacy in older patients. Five trials corresponded to CMR type I (prescription only review) or II (adherence review), whereas four corresponded to type III (comprehensive clinical evaluation for disease management). Type I/II increased the number of unplanned hospitalizations (RR 1.22, 95% CI 1.07-1.38, P = 0.002), whereas type III decreased hospital admissions (RR 0.86, 95% CI 0.79-0.95, P = 0.001). CONCLUSIONS: The present findings show the need for an intervention standardization for CMR, particularly for type III in older adults with polypharmacy, to decrease hospitalizations. Geriatr Gerontol Int 2019; 19: 1275-1281.

Rate of Upper Extremity Injury in High School Baseball Pitchers Who Played Catcher as a Secondary Position.

CONTEXT: Many high school pitchers play another position after they have finished pitching for the day or on their rest days from pitching. Because of the cumulative demands on the arm, pitchers who also play catcher may have a greater risk of developing a throwing-related shoulder or elbow injury. OBJECTIVE: To compare the rate of throwing-related upper extremity injuries between high school baseball pitchers who also played catcher as a secondary position and those who did not play catcher. DESIGN: Prospective cohort study. SETTING: Field laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 384 male high school baseball pitchers were recruited from 51 high school teams. Pitchers who reported their secondary position as catcher were classified into the pitcher/catcher group and those who did not report playing catcher as a secondary position were classified into the other group. MAIN OUTCOME MEASURE(S): Participants completed a demographic questionnaire preseason and then athlete participation and injury status were tracked during the subsequent season. Athlete-exposures were monitored and the shoulder and elbow injury proportion rates were calculated. RESULTS: Athlete-exposures did not differ between groups ( P = .488). The pitcher/catcher group's risk of shoulder or elbow injury was 2.9 times greater than that of the other pitchers (15% versus 5%; injury proportion rate = 2.9; 95% confidence interval = 1.03, 8.12). CONCLUSIONS: Pitchers who reported also playing catcher were at a greater risk of sustaining a throwing-related shoulder or elbow injury than the other pitchers. These findings suggest that pitchers should consider not playing catcher as their secondary position in order to allow adequate time for recovery and to decrease their overall throwing load. Serial physical examinations of pitchers/catchers during the season may be useful in determining if their physical characteristics are changing during the season because of the cumulative throwing load.