Sports Injury Research Research Articles

Classifying sports medicine diagnoses: a comparison of the International classification of diseases 10-Australian modification (ICD-10-AM) and the Orchard sports injury classification system (OSICS-8)

Background: The International classification of diseases 10-Australian modification (ICD-10-AM) and the Orchard sports injury classification system (OSICS-8) are two classifications currently being used in sports injury research. Objectives: To compare...

Ground-Reaction Forces during Form Skipping and Running

Context:Form skipping has been used to help injured athletes progress to running. Because little research has been done on form-skipping mechanics, its justification as a progression to running exercises is unclear.Objective:To compare ground-reaction forces (GRF) during form skipping and running in healthy subjects at clinically relevant speeds, 1.75 m/s and 3.83 m/s, respectively.Design:Dependent t tests (α = .05).Setting:Sports-injury research center.Participants:9 male college athletes (age 20 ± 1.33 years, mass 848.4 ± 43.24 N, height 1.80 ± 0.07 m).Main Outcome Measures:Average (Fzavg) and maximum (Fzmax) vertical GRF and (Fy) braking impulse were compared.Results:Fzavg and Fzmax were greater during running than during form skipping (P < .05). Braking impulses were not different (P > .05).Conclusions:It appears that Fz, but not the Fy, GRF might explain why form skipping might be an appropriate progression to running.

Effects of Altering Intensity during 1-MHz Ultrasound Treatment on Increasing Triceps Surae Temperature

Context:It has been suggested that to obtain optimal physiological effects of heating, musculoskeletal temperature (TEMP) should be elevated 3 °C above baseline and maintained for at least 5 min.Objective:To identify a multi-intensity ultrasound protocol that will achieve optimal heating.Design:1 × 2 between-subjects.Setting:Sports-injury research laboratory.Participants:20 healthy volunteers.Interventions:A 2.5-min treatment at 2.4 W/cm2 immediately followed by a 7.5-min treatment at 1.0 W/cm2 (T1) and a 10-min treatment at 1.5 W/cm2 (T2).Outcome Measures:TEMP change during the first 2.5 min of ultrasound treatment (°C), time the TEMP was ≥3 °C above baseline during and after the treatment.Results:T1 increased TEMP during the first 2.5 min of the ultrasound treatment (3.22 ± 1.25 °C) more than T2 did (1.68 ± 0.72 °C). No difference was found for the remaining measures.Conclusions:The multi-intensity protocol (2.4 W/cm2 and 1.0 W/cm2) did not result in optimal heating.

Catastrophic Injuries in High School and College Baseball Players

Background There are few epidemiologic studies of catastrophic baseball injuries. Purpose To develop a profile of catastrophic injuries in baseball players and to describe relevant risk factors. Study Design Retrospective cohort study. Methods The authors reviewed 41 incidents of baseball injuries reported to the National Center for Catastrophic Sports Injury Research from 1982 until 2002. Results There were an estimated 1.95 direct catastrophic injuries per year, or 0.43 injuries per 100,000 participants. The most common mechanisms of injury were a collision of fielders (9) or of a base runner and a fielder (8), a pitcher hit by a batted ball (14), and an athlete hit by a thrown ball (4). Catastrophic injuries included 23 severe head injuries, 8 cervical injuries, 3 cases of commotio cordis, and 2 cases each of a collapsed trachea and facial fractures. Three athletes sustained a severe head injury and facial fractures. Ten of the 41 injuries were fatalities. Conclusions Suggestions for reducing catastrophic injuries in baseball include teaching proper techniques to avoid fielding and base running collisions, protecting the pitcher via a combination of screens and/or helmets with faceguards, continued surveillance and modifications of the bat and ball, eliminating headfirst slides, and continued analysis of chest protectors and automatic external defibrillators for commotio cordis.

Catastrophic Cheerleading Injuries -- Nothing to Cheer About!

Over the past several years, cheerleading has evolved into an activity requiring enhanced physical prowess and physical maneuvers that place the cheerleader at risk for serious injury. These U.S. investigators reviewed 29 of 39 catastrophic cheerleading injuries (27 in female athletes) that were reported to the National Center for Catastrophic Sports Injury Research from 1982 to …

Catastrophic cheerleading injuries.

There are few epidemiologic studies of cheerleading injuries. To develop a profile of catastrophic injuries in cheerleading and to describe relevant risk factors. Retrospective cohort study. We reviewed 29 of 39 incidents of cheerleading injuries reported to the National Center for Catastrophic Sports Injury Research from 1982 to 2002. Twenty-seven of the injured cheerleaders were women. There were 1.95 direct catastrophic injuries per year or 0.6 injuries per 100,000 participants. The rate of injuries among college cheerleaders was five times that of high school participants. The most common stunts performed at the time of injury were a pyramid (9) or a basket toss (8). Catastrophic injuries included 17 severe head injuries, resulting in 13 skull fractures and 2 deaths; 8 cervical fractures or major ligament injuries; 3 spinal cord contusions; and 1 concomitant head injury and cervical fracture. Suggestions for reducing catastrophic injuries in cheerleaders include enhancing the number and training of spotters, mandating floor mats for complex stunts, restricting complex stunts when surfaces are wet, and encouraging safety certification of coaches. Pyramids and basket tosses should be limited to experienced cheerleaders who have mastered all other skills and should be performed with spotters and landing mats.

Catastrophic spine injuries in American football, 1977-2001.

Cervical spinal cord injuries have been the most common catastrophic football injury and the second leading direct cause of death attributable to football skills. This study looks at the 25-year (1977-2001) experience with catastrophic neck injuries and examines not only the incidence but also the cause of injury and variables that have either increased or decreased these injuries. Data were collected on a national level from all organized football programs, including public school, college, professional, and youth programs, through personal contact and questionnaires on each catastrophic football injury. Funded by the National Collegiate Athletic Association, the National Federation of State High School Associations, and the American Football Coaches Association, data were collected by the National Center for Catastrophic Sports Injury Research, University of North Carolina at Chapel Hill (Frederick O. Mueller, Director, and Robert C. Cantu, Medical Director). Teaching the fundamental techniques of the game, equipment standards, and improved medical care both on and off the playing field have led to a 270% reduction in permanent spinal cord injury from a peak of 20 per year during the period 1971 to 1975 to 7.2 per year during the past 10 years. The type of injury, activity at the time of injury, level of play, and whether the injury was incurred in a game or practice are presented. On the basis of the data, recommendations are given for reducing catastrophic cervical spine injury in football.

The effect of a simulated knee joint effusion on postural control in healthy subjects

Palmieri RM, Ingersoll CD, Cordova ML, Kinzey SJ, Stone MB, Krause BA. The effect of a simulated knee joint effusion on postural control in healthy subjects. Arch Phys Med Rehabil 2003;84:1076-9. Objective:To determine the effects of a simulated knee joint effusion on center of pressure (COP) path and mean power frequency (MPF) during standing. Design:Quasi-experimental design. Setting:Sports injury research laboratory in a university setting. Participants:Twenty healthy volunteers, 10 of whom (age, 20.1±2.4y; height, 168.0±8.1cm; weight, 70.4±13.3kg) were assigned to an effusion group and 10 of whom (age, 25±3.8y; height, 169.4±8.9cm; weight, 74.7±7.7kg) were assigned to a control group. Interventions:COP data were collected before and after a 60-mL injection of sterile saline into the knee joint space. Main Outcome Measures:COP path and mediolateral and anteroposterior MPF. Results:COP path decreased after the effusion (pre-effusion mean, 92.2±21.9cm; posteffusion mean, 77.27±23.0cm). No change was found within the control group for COP path (P>.05). No differences were detected before or after joint effusion when the MPF was examined (P>.05). Conclusions:Possible explanations for the improved postural control after the effusion include additional somatosensory feedback, an augmented neural drive to the soleus, and/or increased capsular tension.

Athletic head injury.

Address: National Center for Catastrophic Sports Injury Research, John Cuming Building, Suite 820, 131 ORNAC, Concord, MA 01742, USA. E-mail: [email protected]

Catastrophic sports injuries: who is at risk?

Address: University of North Carolina at Chapel Hill, Department of Exercise and Sport Science, National Center for Catastrophic Sports Injury Research, CB 8700, 204 Fetzer Gymnasium, Chapel Hill, NC 27599-8700, USA. E-mail: [email protected]

Sports injury prevention: From research to policy and practice

The author's study sought to address the lack of sports injury research of non-elite athletes by developing sports injury prevention policy and best practice training guidelines for Australian football, field hockey and netball. She discusses the problem of data analysis and choosing the model of best fit. (non-author abstract)

Catastrophic injuries in wrestlers.

There is a paucity of comprehensive information on catastrophic wrestling injuries. Our objective was to develop a profile of catastrophic injuries in wrestling and a list of relevant risk factors. Retrospective review. We retrospectively reviewed 35 incidents that were reported to the National Center for Catastrophic Sports Injury Research over an 18-year period from 1981 until 1999. Except in the case of one male college athlete, all injuries occurred in male high school wrestlers. There were 2.11 direct catastrophic injuries per year or 1 per 100000 participants. The majority of injuries occurred in match competitions (80%), with a trend toward more injuries in the low- and middle-weight classes. The position most frequently associated with injury was the defensive position during the takedown maneuver (74%), followed by the down position (23%), and the lying position (3%). Catastrophic injuries included 27 cervical fractures or major cervical ligament injuries, 4 spinal cord contusions with transient quadriparesis, 3 severe head injuries, and an acutely herniated lumbar disc. The injuries resulted in quadriplegia in 11, residual neurologic deficits in 6, paraplegia in 1, and death in 1 head-injured athlete. Although catastrophic injuries in wrestling are rare, they do occur. Referees can help prevent such injuries by strictly enforcing penalties for slams and by gaining more awareness of dangerous holds. Coaches may also prevent serious injuries by emphasizing proper wrestling techniques.

Subcutaneous adipose tissue thickness alters cooling time during cryotherapy

Otte JW, Merrick MA, Ingersoll CD, Cordova ML. Subcutaneous adipose tissue thickness alters cooling time during cryotherapy. Arch Phys Med Rehabil 2002;83:1501-5. Objective: To determine if differing subcutaneous adipose thickness alters the treatment duration required to produce a standard cooling effect during cryotherapy. Design: A 4-group, between-groups comparison in which the independent variable was skinfold thickness (0–10mm, 11–20mm, 21–30mm, 31–40mm) and the dependent variable was cooling time, defined as the treatment duration required to decrease intramuscular (IM) temperature 7°C from baseline. Setting: A sports injury research laboratory. Participants: Forty-seven volunteers with anterior thigh skinfold measurement of less than 40mm. Intervention: Topical cryotherapy (750g crushed-ice bag) to the anterior thigh to produce a typical cooling effect, defined as IM temperature at 1cm subadipose declining by 7°C. Main Outcome Measure: Cryotherapy treatment duration required to produce a standardized cooling effect in subjects with differing subcutaneous adipose thickness. Results: Analysis of variance revealed that mean time to cool IM tissues by 7°C differed across all groups, with cooling time increasing as adipose thickness increased. The mean ± standard deviation cooling times were as follows: 31–40mm (58.6±11.7min), 21–30mm (37.8±9.6min), 11–20mm (23.3±6.7min), and 0–10mm (8.0±3.4min). Conclusions: During cold application, there is a clinically important direct relationship between adipose thickness and required cooling time. This relationship necessitates dramatic adjustments to cryotherapy duration to produce similar IM temperature changes. A 25-minute treatment may be adequate for a patient with a skinfold of 20mm or less; however, a 40-minute application is required to produce similar results in a patients with skinfolds between 21 and 30mm, whereas a 60-minute application is required for patients with skinfolds of 30 to 40mm. © 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

An operational model to investigate contact sports injuries.

A cyclical operational model is proposed to examine the interrelationship of a number of factors that are involved in sports injury epidemiology. In sports injury research, investigations often attempt to identify a unique risk factor that distinguishes an injured player. However, a wide variety of factors can contribute to a sports injury occurring, and an understanding of the cause of injury is important to advance knowledge. The proposed model identifies a healthy/fit player initially, although the player may exhibit a number of intrinsic risk factors for sports injury. Before exposure to extrinsic risk factors, there is the opportunity for implementation of prevention strategies by coaching personnel and the sports medicine team. These strategies might include, among others, appropriate warm-up, adequate hydration, wearing protective equipment, and prophylactic taping. Additionally, preventative screening could take place to assess the various intrinsic and extrinsic risk factors that could lead to sports injury. Two examples of how the operational model relates to contact sports injury cases are presented. Participating in sport inevitably exposes the player to external risk factors that predispose toward injury. The treatment of the injured player aims to restore the player to preinjury playing status and to prevent the injury from becoming chronic. It is suggested that the application of this proposed cyclical model may lead to greater success in understanding the multifaceted nature of sports injuries and furthermore help minimize injury risk and support the rehabilitation of injured contact sports participants.

The relationship between intramuscular temperature, skin temperature, and adipose thickness during cryotherapy and rewarming

ABSTRACT Jutte LS, Merrick MA, Ingersoll CD, Edwards JE. The relationship between intramuscular temperature, skin temperature, and adipose thickness during cryotherapy and rewarming. Arch Phys Med Rehabil 2001;82:845-50. Objective: To describe the relationships among muscle temperature, skin temperature, room temperature, body core temperature, time, and subcutaneous adipose thickness during cryotherapy and rewarming. Design: A multiple linear regression with 5 independent variables (skin temperature, body core temperature, subcutaneous adipose thickness, room temperature, time) predicting intramuscular (IM) temperature. Setting: A sports injury research laboratory. Participants: Fifteen volunteers with thigh skinfold measurements smaller than 40 mm. Interventions: Thirty-minute cryotherapy treatment (ice bag) followed by a 120-minute rewarming period. Main Outcome Measures: The relationship between skin and IM temperature was described, and an equation predicting IM temperature by using room temperature, skin temperature, body core temperature, time, and adipose thickness was developed. Results: Pearson's correlations between each predictor variable of IM temperature during cryotherapy were skin temperature, r =.46; skinfold, r =.37; time, r = −.59; core temperature, r =.21; and room temperature, r = −.47. During rewarming, the correlations were skin temperature, r =.71; skinfold, r =.27; time, r =.76; core temperature, r = −.05; and room temperature, r = −.21. A multiple regression equation (R2 =.76) was developed to predict IM temperature during cryotherapy. A separate equation (R2 =.81) was developed to predict muscle temperatures during rewarming. Conclusions: During and after ice application, no single predictor adequately explained the change in IM temperature. Skin surface temperature was a weak predictor of IM temperature during cryotherapy and should not be used as the sole dependent measure in cryotherapy efficacy studies.

SPORTS INJURY EPIDEMIOLOGY AMONG HIGH SCHOOL ATHLETES

According to the National Federation of State High School Associations, participation of high school athletes in interscholastic sports has risen annually since 1983, with approximately 6.5 million high school athletes (2.6 million female athletes) competing in sports in the USA during the 1998–9 school year (NFSHSA). With increased participation in sports, the number of high school athletes at risk for injuries is also likely to increase. Recently, an estimated 1.3 million high school sports injuries were reported (J Athl Train). Surprisingly, the literature on high school sports injury epidemiology is limited to selected sports and levels of participation. Thus, injury surveillance and analytic studies in high school sports are greatly needed, especially in the area of player-related risk factors. The symposium's purpose will be to identify and recommend how future high school sports injury epidemiological studies/interventions should be conducted so that sports medicine professionals and athletic directors may implement preventive measures and allocate resources well. Objectives include highlighting previous studies and addressing future needs in: epidemiological methodology, comparison of injury rates/risks among boys and girl athletes in similar sports, injury studies specific to female athletes, catastrophic high school injuries, and the physician's role in high school sports injury research. The symposium may help to recommend guidelines in high school sports injury epidemiology.

Catastrophic injuries in pole-vaulters.

Pole vaulting is a unique sport in that athletes often land from heights ranging from 10 to 20 feet. We retrospectively reviewed 32 catastrophic pole-vault injuries that were reported to the National Center for Catastrophic Sports Injury Research between 1982 and 1998. The purpose of this study was to determine the mechanisms of injury so that preventive strategies can be implemented. Information was obtained by means of a telephone interview with someone familiar with the accident. All injuries occurred in male athletes at an average age of 17.5 years; 31 were catastrophic head injuries and 1 was a thoracic spine fracture that resulted in paraplegia. Three common mechanisms were identified: 17 (53%) athletes landed with their body on the landing pad and their head on the surrounding hard ground, 8 (25%) landed in the vault box after being stranded at the height of the jump, and 5 (16%) completely missed the landing pad. The mechanism of injury in the remaining two athletes was unknown. The accident resulted in death in 16 (50%) athletes and in permanent disability in 6 (19%). Increasing the minimum landing pad size and enforcing the rule requiring soft surfaces adjacent to the landing pads are the primary recommendations for preventing injuries. The authors discuss other rule and equipment changes that may help reduce the occurrence of future injuries.

Changes in soleus motoneuron pool excitability after artificial knee joint effusion

Hopkins JT, Ingersoll CD, Edwards JE, Cordova ML. Changes in soleus motoneuron pool excitability after artificial knee joint effusion. Arch Phys Med Rehabil 2000;81:1199-1203. Objective: To compare changes in the magnitude of soleus motoneuron excitability before and over a 4-hour period following artificial knee effusion. Design: Before-after trial. Setting: All measurements were collected in the Sports Injury Research Laboratory, Indiana State University. Participants: Eleven healthy and neurologically sound volunteers (mean age ± SD, 24 ± 3yr; height, 173.2 ± 9.6cm; weight, 72.9 ± 8.7kg) with no history of lower-extremity surgery and no lower extremity pathology in the last year. Interventions: An area superolateral to the patella was cleaned and injected subcutaneously with 2mL of lidocaine for anesthetic purposes. With a second disposable syringe, 25mL of sterile saline was injected through the superolateral knee joint capsule into the joint space to mimic mechanical joint effusion. Main Outcome Measure: Hoffmann's reflex (H-reflex) was elicited by applying a percutaneous stimulus to the tibial nerve in the popliteal fossa. Seven to 12 stimuli were delivered at 20-second intervals with varying intensities to find the maximal H-reflex. The maximal H-reflex was measured five times at the same stimulus intensity with 20-second rest intervals. This measurement was recorded before injection and at 1-hour intervals following the injection for 4 hours. Results: An overall difference between groups was found. Measurements from hours 3 and 4 were significantly higher than the preinjection measurements (p ≤.05). Conclusions: The soleus motoneuron pool was not inhibited as expected. The soleus was facilitated beyond the preinjection level, showing that the quadriceps and soleus do not respond in the same way to artificial knee effusion. Because the quadriceps are normally inhibited during knee effusion, this facilitation could be the result of a compensatory reaction by the soleus in response to inhibited quadriceps. Further studies must be performed to determine the extent and duration of soleus motoneuron pool excitability in relation to quadriceps inhibition elicited by artificial knee effusion. © 2000 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

Sports injury surveillance systems. 'One size fits all'?

Sport is beneficial to health, but may also cause injuries. Therefore there is a need for sports injury prevention. Sports injury prevention should be based on the outcome of scientific research and should be part of the 'sequence of prevention'. In applying the 'sequence of prevention', first the incidence and severity of the sports injury problem need to be established. Secondly the aetiology and the mechanism of sports injuries need to be identified. Only based on this information can preventative measures be introduced, which must subsequently be evaluated for effectiveness. The principle of the 'sequence of prevention' cannot be applied without proper sports injury surveillance. This paper addresses the question of whether one uniform sports injury surveillance system can be used to cover all aspects of sports injury research at all stages of the 'sequence of prevention'. It is argued that a general sports injury surveillance system is useful for answering questions about the incidence and severity of the sports injury problem in various subsets of a population. It can also be used for time trend studies. If the purpose of injury surveillance is to identify the aetiology or the effectiveness of preventative measures, then sports injury surveillance should be tailored to the specific sports situation. Sports injury surveillance systems are not useful in identifying the mechanism of injury.

Nontraumatic sports death in high school and college athletes

Nontraumatic deaths occur each year in organized high school and college athletics, resulting in considerable public concern. We conducted a study of the frequency and causes of nontraumatic sports deaths in high school and college athletes in the USA through the National Center for Catastrophic Sports Injury Research to define the magnitude of this problem and its causes. Over a 10-yr period, July 1983-June 1993, nontraumatic sports deaths were reported in 126 high school athletes (115 males and 11 females) and 34 college athletes (31 males and 3 females). Estimated death rates in male athletes were fivefold higher than in female athletes (7.47 vs 1.33 per million athletes per year, P < 0.0001), and twofold higher in male college athletes than in male high school athletes (14.50 vs 6.60 per million athletes per year, P < 0.0001). Cardiovascular conditions were more common causes of death than noncardiovascular conditions. Hypertrophic cardiomyopathy and congenital coronary artery anomalies were the most common causes of death. In high school and college athletes, males are at increased risk for nontraumatic sports deaths compared with females even after adjustment for participation frequency; college males are at greater risk than high school males. In all groups the deaths were primarily due to cardiovascular conditions.