Profiling injuries sustained following implementation of a progressive load carriage program in United States marine corps recruit training.

BACKGROUND: Load carriage tasks during United States Marine Corps (USMC) recruit training can cause injury. Load carriage conditioning, if optimized, can reduce injury risk. OBJECTIVE: To compare injuries sustained by USMC recruits following participation in either the Original Load Carriage (OLC) program or a Modified Load Carriage (MLC) program. METHODS: Retrospective musculoskeletal injury data were drawn from the USMC San Diego Sports Medicine injury database for recruits completing the OLC (n = 2,363) and MLC (n = 681) programs. Data were expressed as descriptive statistics and a population estimate of the OLC:MLC relative risk ratio (RR) was calculated. RESULTS: The proportion of injuries sustained in the MLC cohort (n = 268; 39% : OLC cohort, n = 1,372 : 58%) was lower, as was the RR (0.68, 95% CI 0.61- 0.75). The leading nature of injury for both cohorts was sprains and strains (OLC n = 396, 29%; MLC n = 66; 25%). Stress reactions were proportionally higher in MLC (n = 17, 6%; OLC n = 4, 0.3%), while stress fractures were proportionately lower (MLC n = 9, 3%; OLC n = 114, 8%). Overuse injuries were lower in MLC (- 7%). The knee, lower leg, ankle, and foot were the top four bodily sites of injuries and the Small Unit Leadership Evaluation (SULE), Crucible, overuse-nonspecific, running, and conditioning hikes were within the top five most common events causing injury. The prevalence rates of moderate severity injury were similar (MLC = 23%; OLC = 24%), although MLC presented both a higher proportion and prevalence of severe injuries (MLC = 6%; OLC = 3%, respectively). CONCLUSION: A periodized load carriage program concurrently increased exposure to load carriage hikes while reducing injuries both during the load carriage hikes and overall.

Biceps muscle injury associated with non-invasive automatic blood pressure monitoring.

This case describes a young, healthy woman who developed a grade 1 biceps muscle strain after the use of automatic non-invasive blood pressure monitoring during an elective surgical procedure. She was treated conservatively with simple analgesia, physiotherapy and a sling for comfort. Follow-up conducted 1 week later revealed occasional soreness, but she had almost returned to her baseline activity. The patient made a full recovery without any residual symptoms by the end of 6 weeks. This case highlights the importance of careful monitoring to ensure that routine use of blood pressure cuffs does not cause any pressure injuries.

The Burden of the "Simple Ankle Sprains": A Review of the Epidemiology and Long-Term Impact.

Lateral ankle sprain (LAS) is not as simple as it was believed to be as it has substantial negative impacts on the active sporting population. The negative impact on physical function, quality of life (QoL) and economic burden is significant with increased risk of reinjury, development of chronic lateral ankle instability and posttraumatic ankle osteoarthritis resulting in functional deficits, decreased QoL and chronic disabilities. Economic burden from a societal perspective demonstrated notably higher indirect costs from productivity loss. Preventative interventions with early surgery for a selective cohort of active sporting population may be considered to mitigate morbidities associated with LAS.

Knee Ligament Sprains: Diagnosing Anterior Cruciate Ligament Injuries by Patient Interview. Development and Evaluation of the Anterior Cruciate Ligament Injury Score (ACLIS).

BACKGROUND: Knee ligament sprains are a common reason for emergency-room visits. Initially, the often difficult physical examination provides limited information, creating a risk of missing cruciate-ligament injuries, which can result in substantial functional impairments. No simple tool is available to emergency and primary-care physicians for decisions regarding specialist referral of patients with knee ligament sprains. An easy to use clinical score for the emergency setting would help identify patients at high risk of anterior cruciate ligament (ACL) tears after knee ligament sprains. The primary objective of this study, in two separate cohorts with acute knee injuries, was to develop, then validate a score for assessing the probability of ACL tear and, therefore, the need for specialist referral. HYPOTHESIS: A score based on patient-interview information with a cut-off associated to good sensitivity and positive predictive value (PPV) for ACL tears can be developed. MATERIAL AND METHODS: A literature review identified seven items to be used in the score: pivoting and contact activity at the time of injury, perceived cracking sound, sensation of dislocation, joint effusion, suggestive mechanism, inability to resume the activity, and immediate sensation of instability upon walking. To select the most relevant items, we recruited a development cohort of 228 patients (127 males and 101 females) with a mean age of 32±9 years who were seen for knee injuries between November 2017 and November 2018 at three healthcare institutions; 183 (80%) had ACL tears. The score was then tested in a validation cohort of 121 patients (79 males and 42 females) with a mean age of 28±2.5 years seen at two healthcare institutions between November 2019 and November 2020; 81 (67%) had ACL tears. In all patients, the diagnosis of ACL tear was confirmed by a specialist examination and magnetic resonance imaging. RESULTS: Four items proved both sensitive and specific for ACL injury and were combined into the score: an immediate sensation of knee instability, an inability to resume the sports activity, a sensation of dislocation, and injury during a pivoting-contact activity. Patient report of two or more of these four criteria had 96% sensitivity and 66% specificity for ACL tear, with a PPV of 91% and an NPV of 83%. Results were similar in the validation cohort, confirming that a cut-off of at least two of the four items strongly suggested an ACL tear, with 94% sensitivity, 56% specificity, a PPV of 82% and an NPV of 82%. CONCLUSION: The ACLIS score performs well for the emergency-room diagnosis of ACL tear, with 95% sensitivity, 62% specificity, an 88% PPV, and an 82% NPV. Patients with ACLIS scores of 2 or more probably require specialist referral with or without magnetic resonance imaging. The ACLIS score could be used routinely in emergency departments to decrease the proportion of patients with undiagnosed ACL tears. LEVEL OF EVIDENCE: III, prospective case-control study of a diagnostic score.

Intubation Biomechanics: Clinical Implications of Computational Modeling of Intervertebral Motion and Spinal Cord Strain during Tracheal Intubation in an Intact Cervical Spine.

BACKGROUND: In a closed claims study, most patients experiencing cervical spinal cord injury had stable cervical spines. This raises two questions. First, in the presence of an intact (stable) cervical spine, are there tracheal intubation conditions in which cervical intervertebral motions exceed physiologically normal maximum values? Second, with an intact spine, are there tracheal intubation conditions in which potentially injurious cervical cord strains can occur? METHODS: This study utilized a computational model of the cervical spine and cord to predict intervertebral motions (rotation, translation) and cord strains (stretch, compression). Routine (Macintosh) intubation force conditions were defined by a specific application location (mid-C3 vertebral body), magnitude (48.8 N), and direction (70 degrees). A total of 48 intubation conditions were modeled: all combinations of 4 force locations (cephalad and caudad of routine), 4 magnitudes (50 to 200% of routine), and 3 directions (50, 70, and 90 degrees). Modeled maximum intervertebral motions were compared to motions reported in previous clinical studies of the range of voluntary cervical motion. Modeled peak cord strains were compared to potential strain injury thresholds. RESULTS: Modeled maximum intervertebral motions occurred with maximum force magnitude (97.6 N) and did not differ from physiologically normal maximum motion values. Peak tensile cord strains (stretch) did not exceed the potential injury threshold (0.14) in any of the 48 force conditions. Peak compressive strains exceeded the potential injury threshold (-0.20) in 3 of 48 conditions, all with maximum force magnitude applied in a nonroutine location. CONCLUSIONS: With an intact cervical spine, even with application of twice the routine value of force magnitude, intervertebral motions during intubation did not exceed physiologically normal maximum values. However, under nonroutine high-force conditions, compressive strains exceeded potentially injurious values. In patients whose cords have less than normal tolerance to acute strain, compressive strains occurring with routine intubation forces may reach potentially injurious values.

Hamstring and gluteal activation during high-speed overground running: Impact of prior strain injury.

This study examined the spatial patterns of hamstring and gluteal muscle activation during high-speed overground running in limbs with and without aprior hamstring strain injury. Ten active males with arecent (<18 month) unilateral biceps femoris long head (BFLH) strain injury underwent functional magnetic resonance imaging before and immediately after arepeat-sprint running protocol. Transverse relaxation (T2) time, an index of muscle activation, of the BFLH and short head (BFSH), semitendinosus (ST), semimembranosus (SM), gluteus maximus (GMAX) and medius (GMED) was assessed pre-post exercise. No significant between-limb differences in running-induced mean T2 changes were observed (p = 0.949), however, decision tree induction revealed that previously injured limbs were characterised by highly variable intramuscular activation of the ST (SD5.3). T2 times increased more for GMAX than all other muscles (all p< 0.001, d= 0.5-2.5). Further, T2 changes were greater for ST than BFSH, SM, GMED, and BFLH (all p≤ 0.001, d= 0.5-2.9); and were greater for BFLH than BFSH, SM, and GMED (all p< 0.001, d= 1.2-1.6). Athletes display heterogenous patterns of posterior thigh activation when sprinting (GMAX>ST>BFLH>GMED>SM>BFSH) and may exhibit altered intramuscular hamstring activation after returning to sport from BFLH strain injury.

Trunk Injuries in Athletes.

ABSTRACT: Trunk pain is a common cause of performance limitation and time away from sport in athletes. However, atraumatic trunk injuries are underrepresented in medical literature and underrecognized clinically. Delays in diagnosis and initiation of appropriate treatment can increase injury morbidity and return-to-play time. Currently, evidence-based guidelines for diagnosis and treatment of trunk pain in athletes are limited. Thus, we provide an overview of atraumatic sport-related injuries to the thoracic spine (disc herniation, scoliosis, kyphosis), ribcage (bone stress injury, costochondritis, Tietze syndrome, slipping rib syndrome, costovertebral or costotransverse joint dysfunction), and chest and abdominal wall musculature (intercostal, serratus anterior, oblique strains, regional myofascial pain), highlighting sport-specific biomechanical considerations. We aim to increase awareness of these causes of trunk pain among sports medicine providers in an effort to guide diagnostic and treatment recommendations that will ultimately improve overall musculoskeletal health in athletes.

Femoral neck strain prediction during level walking using a combined musculoskeletal and finite element model approach.

Recently, coupled musculoskeletal-finite element modelling approaches have emerged as a way to investigate femoral neck loading during various daily activities. Combining personalised gait data with finite element models will not only allow us to study changes in motion/movement, but also their effects on critical internal structures, such as the femur. However, previous studies have been hampered by the small sample size and the lack of fully personalised data in order to construct the coupled model. Therefore, the aim of this study was to build a pipeline for a fully personalised multiscale (body-organ level) model to investigate the strain levels at the femoral neck during a normal gait cycle. Five postmenopausal women were included in this study. The CT and MRI scans of the lower limb, and gait data were collected for all participants. Muscle forces derived from the body level musculoskeletal models were used as boundary constraints on the finite element femur models. Principal strains were estimated at the femoral neck region during a full gait cycle. Considerable variation was found in the predicted peak strain among individuals with mean peak first principal strain of 0.24% ± 0.11% and mean third principal strain of -0.29% ± 0.24%. For four individuals, two overall peaks of the maximum strains were found to occur when both feet were in contact with the floor, while one individual had one peak at the toe-off phase. Both the joint contact forces and the muscular forces were found to substantially influence the loading at the femoral neck. A higher correlation was found between the predicted peak strains and the gluteus medius (R2 ranged between 0.95 and 0.99) than the hip joint contact forces (R2 ranged between 0.63 and 0.96). Therefore, the current findings suggest that personal variations are substantial, and hence it is important to consider multiple subjects before deriving general conclusions for a target population.

Effects of wrist position on eccentric exercise-induced muscle damage of the elbow flexors.

We tested the hypothesis that the magnitude of changes in indirect muscle damage markers would be greater after maximal elbow flexor eccentric exercise in the supinated (shorter biceps brachii) than neutral wrist (longer) position, and the difference in the magnitude would be associated with greater elongation over contractions for the supinated than neutral position, rather than the initial muscle length. Ten untrained men (21-39 years) performed two bouts of 10 sets of 6 maximal isokinetic eccentric contractions of the elbow flexors in the supinated position for one arm and neutral position for the other arm separated by 2 weeks in a randomized order. Biceps brachii myotendinous junction (MTJ) movements during eccentric contractions were recorded by B-mode ultrasonography, and the displacement from the start to end of each contraction was quantified. Peak torque (supinated: 367.8 ± 112.5 Nm, neutral: 381.5 ± 120.4 Nm) and total work (1816 ± 539 J, 1865 ± 673 J) produced during eccentric contractions were similar between conditions. The average MTJ displacement increased (P < .05) from the 1st set (8.0 ± 2.0 mm) to 10th set (15.8 ± 1.9 mm) for the supinated condition, but no such increase was found in the neutral condition (1st set: 5.1 ± 1.0 mm, 10th set: 5.0 ± 0.8 mm). Changes in indirect muscle damage markers (maximal voluntary isometric contraction torque, range of motion, serum creatine kinase activity, and muscle soreness) after exercise were greater (P < .05) for the supinated than neutral condition. These results suggest that the greater muscle damage marker changes for the supinated than neutral wrist position was associated with the greater muscle lengthening (strain).

Does the Spraino low-friction shoe patch prevent lateral ankle sprain injury in indoor sports? A pilot randomised controlled trial with 510 participants with previous ankle injuries.

BACKGROUND: Lateral ankle sprains are common in indoor sports. High shoe-surface friction is considered a risk factor for non-contact lateral ankle sprains. Spraino is a novel low-friction patch that can be attached to the outside of sports shoes to minimise friction at the lateral edge, which could mitigate the risk of such injury. We aimed to determine preliminary effectiveness (incidence rate and severity) and safety (harms) of Spraino to prevent lateral ankle sprains among indoor sport athletes. METHODS: In this exploratory, parallel-group, two-arm pilot randomised controlled trial, 510 subelite indoor sport athletes with a previous lateral ankle sprain were randomly allocated (1:1) to Spraino or 'do-as-usual'. Allocation was concealed and the trial was outcome assessor blinded. Match and training exposure, number of injuries and associated time loss were captured weekly via text messages. Information on harms, fear-of-injury and ankle pain was also documented. RESULTS: 480 participants completed the trial. They reported a total of 151 lateral ankle sprains, of which 96 were categorised as non-contact, and 50 as severe. All outcomes favoured Spraino with incidence rate ratios of 0.87 (95% CI 0.62 to 1.23) for all lateral ankle sprains; 0.64 (95% CI 0.42 to 0.98) for non-contact lateral ankle sprains; and 0.47 (95% CI 0.25 to 0.88) for severe lateral ankle sprains. Time loss per injury was also lower in the Spraino group (1.8 vs 2.8 weeks, p=0.014). Six participants reported minor harms because of Spraino. CONCLUSION: Compared with usual care, athletes allocated to Spraino had a lower risk of lateral ankle sprains and less time loss, with only few reported minor harms. TRIAL REGISTRATION NUMBER: NCT03311490.

Does Muscle-Tendon Unit Structure Predispose to Hamstring Strain Injury During Running? A Critical Review.

Hamstring strain injury (HSI) remains the most common muscle injury in high-intensity running in humans. The majority of acute HSI occur specifically within the proximal region of the long head of biceps femoris and there is a sustained interest among researchers in understanding the factors that predispose to HSI. The present critical review describes the current understanding of biceps femoris long head (BFlh) structural features that might influence strain injury risk. Inter-individual differences in muscle-tendon architecture and interactions, muscle fiber type and region-specific innervation are likely to influence biceps femoris long head injury risk and might inform why some individuals are at an increased risk of sustaining a HSI during running. However, more research is needed, with future studies focusing on prospective data acquisition, improved computer simulations and direct imaging techniques to better understand the relationship between structural features, hamstring muscle function, and injury risk.

Low-Energy Lisfranc Injuries: When to Fix and When to Fuse.

Lisfranc injuries can be devastating to the athlete and nonathlete. In the athletic population, minor loss of midfoot stability compromises the high level of function demanded of the lower extremity. The most critical aspect of treatment is identifying the injury and severity of the ligamentous/articular damage. Not all athletes are able to return to their previous level of function. With appropriate treatment, a Lisfranc injury does not mandate the cessation of an athletic career. We focus on the diagnosis and an algorithmic approach to treatment in the athlete discussion the controversy of open reduction and internal fixation versus arthrodesis.

Ultrasonography Comparison of the Plantar Fascia and Tibialis Anterior in People With and Without Lateral Ankle Sprain: A Case-Control Study.

OBJECTIVE: The purpose of the present study was to evaluate the thickness of the plantar fascia (PF) at the insertion of the calcaneus and the midfoot and forefoot fascial locations, in addition to the thickness of the tibialis anterior, by ultrasound imaging in individuals with and without lateral ankle sprain (LAS). METHODS: A sample of 44 participants was recruited and divided in 2 groups: 22 feet with a prior diagnosis of grade 1 or 2 LAS (case group) and 22 feet without this condition (healthy group). The thickness and cross-sectional area were evaluated by ultrasound imaging in both groups. RESULTS: Ultrasound measurements of the PF at the calcaneus, midfoot, and forefoot showed statistically significant differences (P < .05), with a decrease in thickness in the LAS group relative to the healthy group. For the thickness and cross-sectional area of the tibialis anterior, no significant differences (P < .05) were observed between groups. CONCLUSION: The thickness of the PF at the calcaneus, midfoot, and forefoot is reduced in individuals with LAS relative to the healthy group.

Intra-abdominal Pressure and Pelvic Floor Health: Should We Be Thinking About This Relationship Differently?

OBJECTIVES: Intra-abdominal pressure (IAP) increases during physical activity. Activities with high IAP are often restricted for women because of potential pelvic floor overloading. Researchers categorize high IAP activities using absolute values (in centimeters of water). Although essential for descriptive purposes, absolute IAP may not be ideal for individualized exercise recommendations. For oxygen consumption, a well-established measure of fitness, exercise scientists use a percentage of the maximal value observed during exercise to create relative exercise intensity prescriptions for an individual. Relative exercise intensity correlates inversely to the maximal value observed. We explore whether this approach and response pattern extend to IAP observed during exercise. METHODS: Fifty-five women completed 16 exercises while wearing a vaginal sensor to measure IAP. The highest mean IAP occurred during seated Valsalva/strain (IAPSTRAIN). We calculated relative IAP (in percent) for each participant by dividing the maximal IAP during each exercise by IAPSTRAIN. We examined relationships between relative IAP and IAPSTRAIN for each activity using Pearson r correlations. RESULTS: Mean age was 30.4 ± 9.4 years, and body mass index was 22.4 ± 2.6 kg/m. For most women, IAP was greater during strain than during exercises. Relative IAPs negatively correlated with IAPSTRAIN. Excluding one exercise because of small sample sizes, r for all others ranged from -0.35 to -0.80, all statistically significant. CONCLUSIONS: The relative IAP responses to many exercises exhibit an inverse relationship to the highest IAP values during strain, consistent with other variables measured during exercise. Relative IAP may provide an alternative to absolute IAP in understanding IAP's effect on pelvic floor health.

Does Unicondylar Knee Arthroplasty Affect Tibial Bone Strain? A Paired Cadaveric Comparison of Fixed- and Mobile-bearing Designs.

BACKGROUND: Unexplained pain in the medial proximal tibia frequently leads to revision after unicondylar knee arthroplasty (UKA). As one of the most important factors for osteogenic adaptive response, increased bone strain following UKA has been suggested as a possible cause. QUESTIONS/PURPOSES: In this study we: (1) performed a cadaver-based kinematic analysis on paired cadaveric specimens before and after mobile-bearing and fixed-bearing UKA; and (2) simultaneously characterized the strain distribution in the anterior and posterior proximal tibia during squatting. METHODS: Five pairs of fresh, frozen full-leg cadaver specimens (four male, one female, 64 years to 87 years) were subjected to a dynamic squatting motion on a kinematic rig to simulate joint loading for a large ROM. Forces were applied to the quadriceps and hamstrings during the simulation while an infrared camera system tracked the location of reflective markers attached to the tibia and femur. Tibial cortical bone strain was measured with stacked strain gauge rosettes attached at predefined anterior and posterior positions on the medial cortex. Pairwise implantation of mobile-bearing (UKAMB) and fixed-bearing implants (UKAFB) allowed a direct comparison of right and left knees from the same donor through a linear mixed model. RESULTS: UKAMB more closely replicated native kinematics in terms of tibial rotation and in AP and mediolateral translation. Maximum principal bone strain values were consistently increased compared with native (anteromedial, mean [± SD] peak strain: 311 µÎµ ± 190 and posterior, mean peak strain: 321 µÎµ ± 147) with both designs in the anteromedial (UKAFB, mean peak strain: 551 µÎµ ± 381, Cohen's d effect size 1.3 and UKAMB, mean peak strain: 596 µÎµ ± 564, Cohen's d effect size 1.5) and posterior (UKAFB, mean peak strain: 505 µÎµ ± 511, Cohen's d effect size 1.3 and UKAMB, mean peak strain: 633 µÎµ ± 424, Cohen's d effect size 2.1) region. However, in the anterolateral region of the medial tibial bone, UKAFB demonstrated the overall largest increase in strain (mean peak strain: 1010 µÎµ ± 787, Cohen's d effect size 1.9), while UKAMB (613 µÎµ ± 395, Cohen's d effect size 0.2) closely replicated values of the native knee (563 µÎµ ± 234). CONCLUSION: In this in vitro cadaver study both UKAMB and UKAFB led to an increase in bone strain in comparison with the native knee. However, in the anterolateral region of the medial tibial plateau, proximal tibial bone strain was lower after UKAMB and UKAFB. Both UKAMB and UKAFB lead to comparable increases in anteromedial and posterior tibial strain in comparison with the native knee. In the anterolateral region of the medial tibial plateau UKA, proximal tibial bone strain was closer to the native knee after UKAMB than after UKAFB. In an attempt to link kinematics and strain behavior of these designs there seemed to be no obvious relation. CLINICAL RELEVANCE: Further clinical research may be able to discern whether the observed differences in cortical strain after UKA is associated with unexplained pain in patients and whether the observed differences in cortical bone strain between mobile-bearing and fixed unicondylar designs results in a further difference in unexplained pain.

A syringe adapter for reduced muscular strain and fatigue.

Workers in hospitals, clinics, and contract research organizations who repetitively use syringes have an increased risk for musculoskeletal disorders. This study developed and tested a novel syringe adapter designed to reduce muscle strain associated with repetitive fluid draws. Three syringe plunger extension methods (ring-finger, middle-finger, and syringe adapter) were studied across twenty participants. Electromyogram signals for the flexor digitorum superficialis and extensor digitorum muscles were recorded. The syringe adapter required 31% of the 90th percentile flexor muscle activity as compared to the ring-finger syringe extension method, and 45% the 90th percentile flexor muscle activity as compared to the middle-finger method (p < 0.001). The greatest differences were observed when the syringe was near full extension. Although the syringe adapter took more time than the other syringe extension methods (1.5 times greater), it greatly helped reduce physical stress associated with repetitive, awkward syringe procedures.

A demographic study of acute injuries in basketball players.

Studies that analyse the epidemiology of acute injuries in basketball players in European countries are limited. The purpose is to present an overview of the incidence of injuries and injury patterns in Flanders and to correlate them to possible intrinsic and extrinsic risk factors. All acute injuries that occurred in Flanders during 2009-2013, collected by the insurance, were analysed. The incidence and parameters such as date of birth, date of occurrence of the injury, gender and diagnosis were evaluated. Injury incidence varied from 7.40% up to 8.45%. Females and players at age 16-17, 14-15 and older than 30 are at higher risk. The ankle/foot region is most frequently injured. There is a higher risk of injury after season-and Christmas break. Age, gender and chronometry are risk factors to get injured. Sprains are the most frequent, while the nkle/foot region is the most susceptible to injury. Studies that analyse the epidemiology of acute injuries in basketball players in European countries are limited. Female players and players at age 16-17, 14-15 and older than 30 are at higher risk to basketball injuries. The ankle/foot region is most frequently injured followed by lower arm and hand. There is a higher risk of injury after season-and Christmas break.

Analysis of 4 Years of Injury in Professional Rodeo.

OBJECTIVE: To analyze injury frequency, density, location, type, mechanism of injury (MOI), activity phase of injury, and injury risk in professional rodeo. DESIGN: Retrospective epidemiological review. SETTING: Professional Rodeo Cowboys Association sanctioned rodeos from 2011 to 2014. PARTICIPANTS: Professional Rodeo Cowboys Association competitors competing in bull riding, bareback riding, saddle bronc riding, team roping, tie-down roping, and steer wrestling. MAIN OUTCOME MEASURES: Injury reports were documented by sports medicine personnel. Variables assessed include event, frequency, density, location, type, MOI, activity phase of injury, and injury density. RESULTS: A total of 2305 injuries from 139,098 competitor exposures (CEs) were reported, demonstrating overall injury density of 16.6 injuries per 1000 CEs (95% confidence interval, 0.016-0.017) and overall risk of injury of 1.69%. Rough stock riders accounted for 88.7% of all injuries. Bull riders, bareback riders, and saddle bronc riders demonstrated injury densities of 48.2, 41.1, and 23.2 injuries per 1000 CEs, respectively. Most injuries (62.9%) were sustained by collisions with the ground or animal, or being stomped on by the animal. Contusions, sprains, and concussions were the most frequent injury types (23.1%, 13.6%, and 11.6%, respectively). Neurological components, knees, and shoulders were the most injured body parts (13.4%, 11.1%, and 11.0%, respectively). Most injuries (36.8%) occurred during or immediately after the dismount. CONCLUSIONS: Rough stock events have the greatest risk of injury in professional rodeo, whereas steer wrestling has the greatest risk of injury for timed event athletes. Medical professionals should use these findings to implement prevention programming where possible.