Sports Health

Wearable performance devices and sensors are becoming more readily available to the general population and athletic teams. Advances in technology have allowed individual endurance athletes, sports teams, and physicians to monitor functional movements, workloads, and biometric markers to maximize performance and minimize injury. Movement sensors include pedometers, accelerometers/gyroscopes, and global positioning satellite (GPS) devices. Physiologic sensors include heart rate monitors, sleep monitors, temperature sensors, and integrated sensors. The purpose of this review is to familiarize health care professionals and team physicians with the various available types of wearable sensors, discuss their current utilization, and present future applications in sports medicine.

Data were obtained from peer-reviewed literature through a search of the PubMed database. Included studies searched development, outcomes, and validation of wearable performance devices such as GPS, accelerometers, and physiologic monitors in sports.

Clinical review.

Level 4.

Wearable sensors provide a method of monitoring real-time physiologic and movement parameters during training and competitive sports. These parameters can be used to detect position-specific patterns in movement, design more efficient sports-specific training programs for performance optimization, and screen for potential causes of injury. More recent advances in movement sensors have improved accuracy in detecting high-acceleration movements during competitive sports.

Wearable devices are valuable instruments for the improvement of sports performance. Evidence for use of these devices in professional sports is still limited. Future developments are needed to establish training protocols using data from wearable devices.

Soccer heading is using the head to directly contact the ball, often to advance the ball down the field or score. It is a skill fundamental to the game, yet it has come under scrutiny. Repeated subclinical effects of heading may compound over time, resulting in neurologic deficits. Greater head accelerations are linked to brain injury. Developing an understanding of how the neck muscles help stabilize and reduce head acceleration during impact may help prevent brain injury.

Neck strength imbalance correlates to increasing head acceleration during impact while heading a soccer ball.

Observational laboratory investigation.

Sixteen Division I and II collegiate soccer players headed a ball in a controlled indoor laboratory setting while player motions were recorded by a 14-camera Vicon MX motion capture system. Neck flexor and extensor strength of each player was measured using a spring-type clinical dynamometer.

Players were served soccer balls by hand at a mean velocity of 4.29 m/s (±0.74 m/s). Players returned the ball to the server using a heading maneuver at a mean velocity of 5.48 m/s (±1.18 m/s). Mean neck strength difference was positively correlated with angular head acceleration (rho = 0.497; P = 0.05), with a trend toward significance for linear head acceleration (rho = 0.485; P = 0.057).

This study suggests that symmetrical strength in neck flexors and extensors reduces head acceleration experienced during low-velocity heading in experienced collegiate players.

Balanced neck strength may reduce head acceleration cumulative subclinical injury. Since neck strength is a measureable and amenable strength training intervention, this may represent a modifiable intrinsic risk factor for injury.

Collegiate football is a high-demand sport in which shoulder injuries are common. Research has described the incidence of these injuries, with little focus on causative factors or injury prevention.

Football athletes who score lower on preseason strength and functional testing are more likely to sustain an in-season shoulder injury.

Prospective, cohort study.

Level 2.

Twenty-six collegiate football players underwent preseason testing with a rotational profile for shoulder range of motion, isometric strength of the rotator cuff at 90° elevation and external rotation in the 90/90 position, fatigue testing (prone-Y, scaption, and standing cable press), and the Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST). Data collected postseason included the type of shoulder injury and the side injured. Logistic regression was used to determine if the testing measures predicted injury, and a receiver operating characteristic curve was constructed to examine the relationship of CKCUEST to injury.

Six athletes sustained shoulder injuries during the season. Predictor variables could significantly predict whether that player would sustain an injury during the season for both the right and left shoulders ( P < 0.05). The variables that were significantly correlated with injury of the right side were forward elevation strength, prone-Y to fatigue, and the CKCUEST ( P < 0.05); on the left, only the CKCUEST was significant ( P < 0.05). The area under the receiver operating characteristic curve for the CKCUEST was 0.86 (ϵ = 0.87, P = 0.01). Using a score of 21 touches, the CKCUEST had a sensitivity of 0.83, a specificity of 0.79, and an odds ratio of 18.75 in determining whether a player sustained a shoulder injury.

For this sample, the combination of preseason strength, fatigue, and functional testing was able to identify football players who would sustain a shoulder injury during the season.

Using a battery of strength, fatigue, and functional testing may be helpful in identifying football players during preseason who are at a higher risk for sustaining a shoulder injury. This information can be used to optimize preseason testing and implementation of injury prevention programs.

The incidence of sports-related concussion in females has been increasing in recent years.

To conduct a meta-analysis on sex-based differences in concussion incidence in various sports and to determine the effects of study design (retrospective vs prospective), setting (competition vs practice), and population (university and above vs high school and below) via a meta-regression.

PubMed (Medline), EMBASE, and Cochrane Library databases were searched from January 2000 to January 2018.

Studies reporting sports-related concussion incidence data for both males and females (age ≥10 years) were included.

Systematic review with meta-analysis and meta-regression.

Level 4.

The rate ratio was calculated as the concussion rate in females/males. Data were pooled using the DerSimonian-Laird random-effects model.

Thirty-eight studies met the eligibility criteria and were included in the meta-analysis. Soccer and basketball demonstrated significantly higher incidence of concussions in females compared with males (rate ratio [95% CI], 1.76 [1.43-2.16] and 1.99 [1.56-2.54], respectively; P < 0.01). Sex-based differences in concussion incidence rates for baseball/softball, ice hockey, lacrosse, swimming/diving, and track and field were not statistically significant. In the meta-regression analysis, there were no significant effects on the rate ratio when evaluating study design, setting, and population.

Concussion incidence rates were significantly higher in females than in males for soccer and basketball.

The posterior shoulder muscles play key roles in maintaining shoulder function in throwing. Arm fatigue has been identified as a risk factor for shoulder and elbow pain in youth baseball pitchers. However, endurance of the posterior shoulder muscles in overhead athletes is not routinely examined or conditioned.

Upper extremity muscular endurance can be improved in adolescent baseball players during a 20-week preseason training program. Secondarily, strength will be improved. Finally, these improvements will be associated with maintenance of range of motion.

Cohort study.

Fourteen baseball players (age, 16 ± 2 years) attended 3 supervised training sessions per week for 20 weeks. Strengthening of the upper extremity was performed with a specific progression that utilized readily available equipment. Testing was completed at baseline and at 4, 8, and 20 weeks. The posterior shoulder endurance test was performed to assess muscular endurance. Glenohumeral internal and external rotation range of motion and strength were measured.

Posterior shoulder endurance improved from 30 ± 14 repetitions at baseline to 66 ± 26 at 4 weeks and 88 ± 36 at 20 weeks ( P < 0.05). Glenohumeral internal rotation range of motion and the glenohumeral internal/external rotation strength ratio remained similar over the course of the program.

Implementation of a preseason training program effectively increased shoulder muscular endurance while maintaining strength ratios and range of motion throughout the 20-week program.

This program improved a key parameter known to be associated with shoulder function and injury risk. This study describes a simple clinical tool to assess muscular endurance of the posterior shoulder.

Physical activity (PA) is beneficial, enhancing healthy development. However, one-third of school-age children practicing sports regularly suffer from an injury. These injuries are associated with sex, chronological age, and PA level.

To identify the importance of age, PA level, and maturity as predictors of injury in Portuguese youth.

Descriptive epidemiological study.

Level 3.

Information about injury and PA level was assessed via 2 questionnaires (LESADO RAPIL II) from 647 subjects aged 10 to 17 years. Maturity offset according to Mirwald (time before or after peak height velocity) and Tanner-Whitehouse III bone age estimates were used to evaluate maturation. Binary logistic regression and gamma regression were used to determine significant predictors of injury and injury rate.

Injury occurrence was higher for both sexes in recreational, school, and federated athletes (athletes engaged in sports that are regulated by their respective federations, with formal competition). These injuries also increased with age in boys and in the higher maturity offset group in girls. Injury rate was higher for both sexes in the no sports participation group. Early-maturing girls, with higher bone age and lower maturity offset, showed higher injury rate.

Injuries in Portuguese youth were related to PA level, age, and biological maturation. Recreational, school, and federated athletes had more injury ocurrences while subjects with no sports participation had higher injury risk. Older subjects had more injuries. Early-maturing girls that had just passed peak height velocity may be particularly vulnerable to risk of sports injury because of the growing process.

Increased knowledge about injury with specific PA exposure data is important to an overall risk management strategy. This study has deepened the association between injury and biological maturation variables.

Only 55% of the athletes return to competitive sports after an anterior cruciate ligament (ACL) injury. Athletes younger than 25 years who return to sports have a second injury rate of 23%. There may be a mismatch between rehabilitation contents and the demands an athlete faces after returning to sports. Current return-to-sports (RTS) tests utilize closed and predictable motor skills; however, demands on the field are different. Neurocognitive functions are essential to manage dynamic sport situations and may fluctuate after peripheral injuries. Most RTS and rehabilitation paradigms appear to lack this aspect, which might be linked to increased risk of second injury.

This systematic and scoping review aims to map existing evidence about neurocognitive and neurophysiological functions in athletes, which could be linked to ACL injury in an integrated fashion and bring an extensive perspective to assessment and rehabilitation approaches.

PubMed and Cochrane databases were searched to identify relevant studies published between 2005 and 2020 using the keywords ACL, brain, cortical, neuroplasticity, cognitive, cognition, neurocognition, and athletes.

Studies investigating either neurocognitive or neurophysiological functions in athletes and linking these to ACL injury regardless of their design and technique were included.

Systematic review.

Level 3.

The demographic, temporal, neurological, and behavioral data revealing possible injury-related aspects were extracted and summarized.

A total of 16 studies were included in this review. Deficits in different neurocognitive domains and changes in neurophysiological functions could be a predisposing risk factor for, or a consequence caused by, ACL injuries.

Clinicians should view ACL injuries not only as a musculoskeletal but also as a neural lesion with neurocognitive and neurophysiological aspects. Rehabilitation and RTS paradigms should consider these changes for assessment and interventions after injury.

Mixed results exist regarding the benefit of orthobiologic injections. The purpose of this study was to assess the variability in costs for platelet-rich plasma (PRP) and stem cell (SC) injections and evaluate for variables that influence pricing.

There will be significant variability in the cost of PRP and SC injections throughout the United States.

Descriptive epidemiology study.

Level 3.

Calls were made to 1345 orthopaedic sports medicine practices across the United States inquiring into the availability of PRP or SC knee injections and associated costs. In addition to pricing, the practice type, number of providers, and population and income demographics were recorded. Univariate statistical analyses were used to identify differences in availability and cost between variables.

Of the contacted offices that provided information on both PRP and SC availability (n = 1325), 268 (20.2%) offered both treatments, 550 (41.5%) offered only PRP injections, 20 (1.5%) offered only SC injections, and 487 (36.8%) did not offer either treatment. The mean ± SD cost of a PRP injection was $707 ± $388 (range, $175-$4973), and the mean cost of an SC injection was $2728 ± $1584 (range, $300-$12,000). Practices offering PRP and SC injections tended to be larger (PRP, 12.0 physicians per practice vs. 8.1 [ P < 0.001]; SC, 13.6 vs 9.7 [ P < 0.001]). Practices that offered PRP injections were located in areas with higher median household income ( P = 0.047). Variables associated with higher cost of PRP injections included city population ( P < 0.001) and median income of residents ( P < 0.001).

While the majority of sports medicine practices across the United States offer some type of orthobiologic injection, there exists significant variability in the cost of these injections.

This study demonstrates the significant variability in costs of orthobiologic injections throughout the country, which will allow sports medicine physicians to appreciate the value of these injections when counseling patients on available treatment options.

We present the current spectrum of postoperative management practices for patients receiving distal femur osteochondral allograft (OCA) transplants.

The Joint Restoration Foundation database was examined in cooperation with the Metrics of Osteochondral Allografts study group to identify 121 surgeons who had performed at least 1 OCA transplant in the past year; 63% of surgeons responded.

Clinical survey.

Level 3.

Postoperative weightbearing restrictions ranged from immediate nonweightbearing with full weightbearing by 12 weeks to immediate weightbearing as tolerated. Most surgeons who performed fewer (<10) OCA transplants per year followed the most restrictive protocol, while surgeons who performed more (>20) OCA transplants per year followed the least restrictive protocol. One-third of surgeons with the most restrictive protocol were more likely to change their protocol to be less restrictive over time, while none of those with the least restrictive protocol changed their protocol over time. Fifty-five percent of surgeons permitted return to full activity at 26 weeks, while 27% of surgeons lifted restrictions at 16 weeks.

Characterization of the spectrum of postoperative management practices after OCA transplantation provides a foundation for future investigations regarding patient outcomes and associated cost to establish best practice guidelines. Fundamentally, surgeons with more experience with this procedure tended to be more aggressive with their postoperative rehabilitation guidelines. Most commonly, rehabilitation provided for some degree of limited weightbearing; however, the spectrum also included immediate full weightbearing practices.