Clinical Journal of Sport Medicine

Published by American Academy of Orthopaedic Surgeons

Print ISSN: 1050-642X


In Response to
  • Article

November 2014


39 Reads

John D Baldea

The Prevention of Sport Injury: An Analysis of 12 000 Published Manuscripts

November 2010


827 Reads


Ian Shrier


Kellen McBain




Gordon O Matheson
To identify the nature and extent of research in sport injury prevention with respect to 3 main categories: (1) training, (2) equipment, and (3) rules and regulations. We searched PubMed, CINAHL, Web of Science, Embase, and SPORTDiscus to retrieve all sports injury prevention publications. Articles were categorized according to the translating research into injury prevention practice model. We retrieved 11 859 articles published since 1938. Fifty-six percent (n = 6641) of publications were nonresearch (review articles and editorials). Publications documenting incidence (n = 1354) and etiology (n = 2558) were the most common original research articles (33% of total). Articles reporting preventive measures (n = 708) and efficacy (n = 460) were less common (10% of the total), and those investigating implementation (n = 162) and effectiveness (n = 32) were rare (1% of total). Six hundred seventy-seven studies focused on equipment and devices to protect against injury, whereas 551 investigated various forms of physical training related to injury prevention. Surprisingly, publications studying changes in rules and regulations aimed at increasing safety and reducing injuries were rare (<1%; n = 63) with a peak of only 20 articles over the most recent 5-year period and an average of 10 articles over the preceding 5-year blocks of time. Only 492 of 11 859 publications actually assessed the effectiveness of sports injury prevention interventions or their implementation. Research in the area of regulatory change is underrepresented and might represent one of the greatest opportunities to prevent injury.

Upper Extremity Sports Injury: Risk Factors in Comparison to Lower Extremity Injury in More Than 25 000 Cases

July 2010


1,448 Reads

To analyze differences in sports injury characteristics of the upper and lower extremity and to identify factors that contribute to the risk of sustaining an upper extremity injury compared with the risk of sustaining a lower extremity injury. Retrospective cohort study. An emergency department of a large European level I trauma center. A total of 25 120 patients with a simple sports injury, attending during 1990-2005. Independent variables used to assess risk factors were extracted from a local database. These include age, sex, type of injury, site and side of the injury, type of sport, injury mechanism, and data on admission. Main outcome measure was the relation of various risk factors to the occurrence of either upper or lower extremity injury. Logistic regression analysis was used to identify predictors for upper extremity injury. Thirty-five percent upper and 53% lower extremity injuries were recorded. Most injuries were sustained when playing soccer (36%). Fractures were more frequently diagnosed in the upper than in the lower extremities (44% and 14%, respectively), especially in children. Falling was the main cause of upper extremity injury. Further risk factors were young age and playing individual sports, no-contact sports, or no-ball sports. Women were at risk in speed skating, inline skating, and basketball, whereas men mostly got injured during skiing and snowboarding. A high percentage of sports injuries are sustained to the upper extremity. Different risk factors were identified for both sexes. These risk factors should be taken into account when designing preventive measures.

Epidemiology of US High School Sports-Related Ligamentous Ankle Injuries, 2005/06-2010/11

January 2013


98 Reads

Objective: Describe ankle injury epidemiology among US high school athletes in 20 sports. Design: Descriptive prospective epidemiology study. Setting: Sports injury data for the 2005/06 to 2010/11 academic years were collected using an Internet-based injury surveillance system, Reporting Information Online. Participants: A nationwide convenience sample of US high schools. Assessment of risk factors: Injuries sustained as a function of sport and gender. Main outcome measures: Ankle sprain rates and patterns, outcomes, and mechanisms. Results: From 2005/06 to 2010/11, certified athletic trainers reported 5373 ankle sprains in 17,172,376 athlete exposures (AEs), for a rate of 3.13 ankle sprains per 10,000 AEs. Rates were higher for girls than for boys (rate ratio [RR], 1.25; 95% confidence interval [CI], 1.17-1.34) in gender-comparable sports and higher in competition than practice for boys (RR, 3.42; 95% CI, 3.20-3.66) and girls (RR, 2.71; 95% CI, 2.48-2.95). The anterior talofibular ligament was most commonly injured (involved in 85.3% of sprains). Overall, 49.7% of sprains resulted in loss of participation from 1 to 6 days. Although 0.5% of all ankle sprains required surgery, 6.6% of those involving the deltoid ligament also required surgery. The athletes were wearing ankle braces in 10.6% of all the sprains. The most common injury mechanism was contact with another person (42.4% of all ankle sprains). Conclusions: Ankle sprains are a serious problem in high school sports, with high rates of recurrent injury and loss of participation from sport.

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Playing Ice Hockey and Basketball Increases Serum Levels of S-100B in Elite Players
  • Article
  • Full-text available

October 2003


133 Reads

To investigate changes in serum concentrations of the biochemical markers of brain damage S-100B and neuron-specific enolase (NSE) in ice hockey and basketball players during games. Descriptive clinical research. Competitive games of the Swedish Elite Ice Hockey League and the Swedish Elite Basketball League. Twenty-six male ice hockey players (from two teams) and 18 basketball players (from two teams). None. S-100B and NSE were analyzed using two-site immunoluminometric assays. The numbers of acceleration/deceleration events were assessed from videotape recordings of the games. Head trauma-related symptoms were monitored 24 hours after the game using the Rivermead Post Concussion Symptoms Questionnaire. Changes in serum concentrations of S-100B (postgame - pregame values) were statistically significant after both games (ice hockey, 0.072 +/- 0.108 microg/L, P = 0.00004; basketball, 0.076 +/- 0.091 microg/L, P = 0.001). In basketball, there was a significant correlation between the change in S-100B (postgame-pregame values) and jumps, which were the most frequent acceleration/deceleration (r = 0.706, P = 0.002). For NSE, no statistically significant change in serum concentration was found in either game. For one ice hockey player who experienced concussion during play, S-100B was increased more than for the other players. S-100B was released into the blood of the players as a consequence of game-related activities and events. Analysis of the biochemical brain damage markers (in particular S-100B) seems to have the potential to become a valuable additional tool for assessment of the degree of brain tissue damage in sport-related head trauma and probably for decision making about returning to play.

Performance Enhancement Effects of Fédération Internationale de Football Association’s “The 11+” Injury Prevention Training Program in Youth Futsal Players

March 2013


612 Reads

Objective: To evaluate if Fédération Internationale de Football Association's "The 11+" injury prevention program improves physical fitness and technical performance in youth futsal players. Design: Randomized cohort study. Setting: Futsal club. Participants: Thirty-six futsal players (17.3 ± 0.7 years). Intervention: Players were randomized to an intervention group (n = 18) or a control group (n = 18). Intervention group performed "The 11+" twice per week for 12 weeks. Main outcome measures: Isokinetic testing to access maximal quadriceps (Q) and hamstring (H) strength, vertical jump (squat jump, SJ; countermovement jump, CMJ), 5-m and 30-m sprint, agility, slalom, and balance performances were also measured. Results: Intervention group increased (P < 0.05) quadriceps concentric (14.7%-27.3%) and hamstrings concentric (9.3%-13.3%) and eccentric (12.7%) peak torque. Intervention group improved functional H:Q ratio by 1.8% to 8.5% (P < 0.05). Intervention group improved (P < 0.05) SJ (13.8%) and CMJ (9.9%) and 5-m and 30-m sprint (8.9% and 3.3%, respectively), agility (4.7%), and slalom (4.8%) performances. Intervention group also improved balance, by decreasing the number of falls by 30% in the nondominant limb. No changes were observed in control group. Conclusions: The results suggest that 'The 11+' can be used as an effective conditioning means for improving physical fitness and technical performance of youth futsal players.

Quadriceps Contusions: Clinical Results of Immediate Immobilization in 120 Degrees of Knee Flexion

October 2006


261 Reads

Quadriceps contusions often result in significant time loss and the possibility of myositis ossificans. The objective of this descriptive case series was to document the results of an initial treatment regimen instituted within 10 minutes from the time of the injury. This study was a prospective case series of 47 midshipmen who sustained quadriceps contusions between August 1987 and December 2005 and who were treated identically and followed by serial examinations until the return to unrestricted full athletic activities. United States Naval Academy (USNA), Annapolis, Maryland. USNA midshipmen who sustained quadriceps contusions while participating in sports activities. Inclusion criteria were (1) stated inability at the time of the injury to continue participation and (2) the inability to perform a pain-free, isometric quadriceps contraction and maintain the knee in full extension with a straight leg lift. On diagnosis the knee was passively flexed painlessly to 120 degrees and held continuously in that position for 24 hours. Use of the brace was discontinued at 24 hours and the midshipman was instructed to perform active, pain-free quadriceps stretching several times a day and to perform pain-free isometric quadriceps strengthening exercises as soon as possible. Goals included pain-free knee flexion and quadriceps size and firmness equal to the uninjured side. Average time from the day of the injury to return to unrestricted full athletic activities with no disability. The average time to return to unrestricted full athletic activities with no disability was 3.5 days (range of 2 to 5 days). Radiographic examination of the first 23 midshipmen at 3 and 6 months following the injury revealed 1 case of myositis ossificans. Placing and holding the knee in 120 degrees of flexion immediately following a quadriceps contusion appears to shorten the time to return to unrestricted full athletic activities compared with reports in other studies.

Injuries Presenting to an Australian Sports Medicine Centre: A 12Month Study

February 1997


468 Reads

To document the conditions seen by medical practitioners at a multidisciplinary sports medicine clinic during a 12-month period on the basis of site of injury, pathology, and sport played. A coding system for anatomical region, pathology, and sport played was designed. The total number of patient diagnoses coded and entered for analysis was 2,429. The most common sports involved were Australian football 322 (13.3%), distance running 299 (12.3%), netball/basketball 210 (8.6%), racquet sports 140 (5.8%), and track running 135 (5.6%). The most commonly injured region was the knee with 668 presentations (27.5%), followed by the upper limb (8.8%). The most frequently diagnosed pathology was overuse/inflammation with 1,115 (45.9%). Other pathologies diagnosed were partial ligament sprains 316 (13.0%), muscle strain 99 (4.1%), compartment syndrome 85 (3.5%), and third-degree ligament tear (3.5%). The most common diagnoses seen were patellofemoral syndrome, lumbar spine disorders, rotator cuff tendinitis, lateral ligament ankle sprain, medial meniscus tear, medial collateral ligament knee sprain, lateral meniscus tear, achilles tendinosis, anterior cruciate ligament tear and sacroiliac joint inflammation. A study of this nature provides valuable information both to the epidemiologist and clinician.

Baseline SCAT2 Assessment of Healthy Youth Student-Athletes: Preliminary Evidence for the Use of the Child-SCAT3 in Children Younger Than 13 Years

October 2014


69 Reads

Objective: To compare baseline scores of middle and high school students on the Sport Concussion Assessment Tool 2 (SCAT2) by sex and age. Design: Cross-sectional study. Setting: Single private school athletic program. Participants: Three hundred sixty-one middle and high school student-athletes. Intervention: Preseason SCAT2 was administered to student-athletes before athletic participation. Main outcome measures: Total SCAT2 score, symptoms, symptom severity, Glasgow coma scale, modified Balance Error Scoring System (BESS), coordination, and Standardized Assessment of Concussion (SAC) with subsections: Orientation, Immediate Memory, Concentration, and Delayed Recall. Results: No differences were found in total SCAT2 scores between sex (P = 0.463) or age (P = 0.21). Differences were found in subcomponents of the SCAT2. Twelve year olds had significantly lower concentration scores (3.3 ± 1.2) than 15 and 18 year olds (3.9 ± 1.0 and 4.2 ± 1.0, respectively). The 12 year olds also had the lowest percentage of correct responses for the SAC's concentration 5-digit (46%), 6-digit (21%), and months' backward (67%) tasks. Females presented with more symptoms (20.0 ± 2.2 vs. 20.6 ± 2.1 P = 0.007) better immediate memory (14.6 ± 0.9 vs. 14.3 ± 1.0, P = 0.022) and better BESS scores (27.2 ± 2.3 vs. 26.6 ± 2.6, P = 0.043) than their male counterparts. Conclusions: Normative values for total SCAT2 and subscale scores show differences in concentration between ages, whereas symptoms, BESS, and immediate memory differed between sexes. We also found that 12 year olds have increased difficultly with the advanced concentration tasks, which lends support to the development of a separate instrument, such as the Child-SCAT3. The presence of developmental differences in the younger age groups suggests the need for annual baseline testing. Clinical relevance: Subtle differences between age and sex have been identified in many components of the SCAT2 assessment. These differences may support the current evolution of concussion assessment tools to provide the most appropriate test. Baseline testing should be used when available, and clinicians should be aware of potential differences when using normalized values.

Effects of High-Intensity Exercises on 13C-Nandrolone Excretion in Trained Athletes

June 2005


27 Reads

Nandrolone is an anabolic steroid widely used in several sports. The numerous nandrolone positive cases in the recent years (International Olympic Committee statistics) led to several studies in the antidoping field. Nevertheless, essential questions pertaining to nandrolone endogenous production, the effects of physical exercise on the excretion of nandrolone metabolites, and contamination from nutritional supplements must still be addressed. The purpose of this study was to evaluate the influence of exhaustive exercises on 19-norandrosterone (19-NA) and 19-noretiocholanolone (19-NE) urinary excretion rates after administration of labeled nandrolone. A total of 34 healthy male Caucasian volunteers from the Institute of Sports Sciences and Physical Education (University of Lausanne) applied to participate in the study. All subjects were free from any physical drug addiction and were instructed strictly to avoid any nutritional supplement or steroid before and during the study. The participants were randomly dispatched in 2 groups in a double-blind way: a placebo group and a group treated with C-labeled nandrolone. The urinary concentrations of the 2 main nandrolone metabolites, 19-NA and 19-NE, were measured using gas chromatography coupled with mass spectrometry. In addition, clinical parameters such as creatinine, total protein, and beta2-microglobuline levels were determined using immunologic assays. After an oral ingestion of a 25 mg 3,4-C2-nandrolone dose, followed by a second identical dose 24 hours later, 19-NA and 19-NE could be detected in the urine for a period of 6 days after the initial intake. Despite several interesting observations, the measurements were very scattered and did not appear to be significantly influenced by exercise sessions in the athlete population. The results of this study suggest that physical exercise cannot be considered as a reliable parameter that systematically affects nandrolone metabolite concentrations in the urine.

MRI-Demonstrated Outcome of Subchondral Stress Fractures of the Knee After Treatment with Iloprost or Tramadol: Observations in 14 Patients

August 2008


128 Reads

To investigate the outcome of subchondral stress fractures (SSF) of the knee after treatment with the prostacyclin analogue Iloprost or the opioid analgesic Tramadol. Case series/retrospective review. Tertiary care center. Fourteen patients with at least a single subchondral stress fracture of the knee, surrounded by bone marrow edema, visible on T1-weighted and short tau inversion recovery magnetic resonance images. Nine patients had been treated with oral Iloprost (group 1; 11 SSF) and 5 patients with Tramadol (group 2; 5 SSF) for 4 weeks in the course of a double-blind, randomized clinical trial. MR images were obtained at baseline (1 day before the start of treatment), after 3 months, and after 1 year. SSF volumes and their rates of change between baseline and follow-up examinations, as determined on T1-weighted images by computer-assisted quantification. After three months, the SSF volumes had decreased by a median of 42.2% in group 1 and increased by a median of 2.2% in group 2 (P = 0.008). After 1 year, the median decrease in SSF volumes was 100.0% in group 1 and 65.7% in group 2 (P = 0.017). This small case series suggests that healing of SSF is more pronounced after Iloprost treatment.

Can 16-18-year-old elite ballet dancers improve their hip and ankle range of motion over a 12-month period?

May 2000


294 Reads

To determine the effect of a 12-month intensive ballet training regimen on hip and ankle range of motion in male and female, first- and second-year professional dancers. 12-month longitudinal follow-up. National classical ballet school in Australia. 28 female and 20 male full-time ballet students with a mean +/- 1 SD, ages 16.8 +/- 0.8 and 17.7 +/- 1.2 years, respectively. Degrees of range of motion of left and right sides for the following movements: standing plié in parallel-passive ankle dorsiflexion (DF); standing turnout in the balletic first position--lower leg external rotation (LLER); supine hip external rotation (ER); supine hip internal rotation (IR). An additional range of motion was calculated: external rotation below the hip joint (BHER) derived by subtracting hip ER from LLER. In all subjects combined, hip and ankle ranges increased statistically on the right. However, the amount was generally minimal and most at the borderline of the amount of error associated with the measurement tool. While there was no change in LLER, there was a decrease in BHER. There were no overall gender differences, and year differences existed only for left hip ER and total hip ER with first-year dancers showing significant improvements in these ranges. For DF and sum of hip IR, first-year males and second-year females had increases in range. There was a negative relationship between baseline range and the amount of change over the 12 months. Dancers ages 16-18 years who enter full-time ballet training did not augment their ankle dorsiflexion to any appreciable degree. Some, but certainly not all, increased their hip active external rotation over 12 months without increasing their total lower limb turnout. Hip ER was more likely to improve in the first-year rather than second-year student in this elite full-time training school.

The Effects of 16 Weeks of Intensive Cycling Training on Seminal Oxidants and Antioxidants in Male Road Cyclists

January 2014


322 Reads

To examine the effects of 16 weeks of intensive cycling training on seminal reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), catalase, and total antioxidant capacity (TAC) in male road cyclists. Repeated measures design. The Exercise Physiology Laboratory of the Urmia University. Twenty-four healthy nonprofessional male road cyclists (aged 17-26 years) participated in this study. All subjects participated in 16 weeks of intensive cycling training. The semen samples were collected, respectively, at baseline (T1), immediately (T2), 12 (T3), and 24 (T4) hours after the last training session in week 8; immediately (T5), 12 (T6), and 24 (T7) hours after the last training session in week 16; and 7 (T8) and 30 (T9) days after the last training session in week 16. Total antioxidant capacity and SOD were measured by colorimetric assay. The levels of ROS were measured by a chemiluminescence assay. Malondialdehyde levels were measured by thiobarbituric acid reactive substance assay. Catalase was measured by monitoring the initial rate of disappearance of hydrogen peroxide (initial concentration 10 mM) at 240 nm. The levels of seminal ROS and MDA increased (P < 0.008) and remained high after 30 days of recovery. The levels of seminal SOD, catalase, and TAC decreased (P < 0.008) and remained low after 30 days of recovery (P < 0.008). Sixteen weeks of intensive cycling training may have deleterious consequences for spermatozoa and hence may affect sperm healthy parameters in male cyclists.

Physiologic Alterations and Predictors of Performance in a 160-km Ultramarathon

March 2012


49 Reads

To describe physiologic alterations in runners competing in a 160-km endurance event and to evaluate the utility of weight and blood pressure measurements in the assessment of runner performance. Prospective cohort study. One hundred sixty-km ultramarathon. Ninety-one of the 101 participants in the 2010 Tahoe Rim 100 Mile Endurance Run. Brachial blood pressure, heart rate, and weight were assessed before competition, at 80 km, and at 160 km. Alterations in brachial blood pressure, heart rate, and weight were assessed in finishers. Weight loss, brachial blood pressure, pulse pressure, and heart rate at 80 km were assessed in all participants for their ability to predict failure to finish the race. Participants who finished 160 km (57%) experienced their fastest heart rates (P < 0.05), lowest systolic pressures (P < 0.05), highest diastolic pressures (P < 0.05), narrowest pulse pressures (P < 0.05), and lowest weights (P < 0.05) at 80 km. High rates of finishing were seen in those who lost >5% of their prerace weight (87%). Categorical weight loss (<3%, 3%-5%, and >5%) was not associated with the ability to finish (P > 0.05) or finishing time (P > 0.05), whereas the presence of a narrow pulse pressure was associated with a high likelihood (likelihood ratio = 9.84; P = 0.002) of failure to finish. Greater intracompetition weight loss is not associated with impaired performance but rather may be an aspect of superior performance. Narrow pulse pressure was associated with a high likelihood of failure to finish.

Can Changes in Body Mass and Total Body Water Accurately Predict Hyponatremia After a 161-km Running Race?

May 2010


125 Reads

To relate changes in body mass, total body water (TBW), extracellular fluid (ECF), and serum sodium concentration ([Na]) from a 161-km ultramarathon to finish time and incidence of hyponatremia. Observational. : The 2008 Rio Del Lago 100-Mile (161-km) Endurance Run in Granite Bay, California. Forty-five runners. Pre-race and post-race body mass, TBW, ECF, and serum [Na]. Body mass and serum [Na] significantly decreased 2% to 3% (P < 0.001) from pre-race to post-race, but TBW and ECF were unchanged. Significant relationships were observed between finish time and percentage change in body mass (r = 0.36; P = 0.01), TBW (r = 0.50; P = 0.007), and ECF (r = 0.61; P = 0.003). No associations were found between post-race serum [Na] and percentage change in body mass (r = -0.04; P = 0.94) or finish time (r = 0.5; P = 0.77). Hyponatremia (serum [Na] < 135 mmol/L) was present among 51.2% of finishers. Logistic regression prediction equation including pre-race TBW and percentage changes in TBW and ECF had an 87.5% concordance with the classification of hyponatremia. Hyponatremia occurred in over half of the 161-km ultramarathon finishers but was not predicted by change in body mass. The combination of pre-race TBW and percentage changes in TBW and ECF explained 87.5% of the variation in the incidence of hyponatremia. Exercise-associated hyponatremia can occur simultaneously with dehydration and cannot be predicted by weight checks at races.

An 18-Year Review of Sports Groin Injuries in the Elite Hockey Player: Clinical Presentation, New Diagnostic Imaging, Treatment, and Results

June 2008


95 Reads

This is a retrospective study of 98 hockey players who underwent 107 surgical explorations for refractory lower abdominal and groin pain that prevented them from playing hockey at an elite level. Retrospective chart review combined with a complete follow-up examination and questionnaire. The players were treated in an ambulatory care university tertiary care centre. A total of 98 elite hockey players underwent 107 surgical groin explorations for intractable groin pain preventing their play. Follow-up was 100%. Each player had repair of a tear of the external oblique muscle and fascia reinforced by a Goretex mesh. The ilioinguinal nerve was resected in each patient. There was absence of groin pain on the return to play hockey at an elite level. In all, 97 of 98 players returned to play after the surgical procedures. No morbidity was attributed to division of the ilioinguinal nerve. Surgical exploration of the involved groin with repair of the torn external oblique muscle and division of the ilioinguinal nerve has resulted in resolution of refractory groin pain and return to play in the elite hockey player. The surgical procedure is associated with a low morbidity. Recent observations on dynamic ultrasound show promise in accurately diagnosing this injury.

Stress fractures: A review of 180 cases

May 1996


2,209 Reads

To review the cases of stress fracture seen over a 2-year period at a sports medicine clinic. One hundred and eighty cases diagnosed as stress fractures on the basis of clinical picture and radiological evidence were reviewed. The following features of each stress fracture were noted: age, sex, site, sport/activity. A sports medicine centre in Melbourne, Australia. The average age was 21.8 years. Seventy eight of these stress fractures were seen in women, 102 in men. The most common sites of stress fractures were the metatarsal bones (n = 42), tibia (n = 36), fibula (n = 30), tarsal navicular (n = 26) and pars interarticularis (n = 17). The most common sport was track (n = 54). Other common sports activities were jogging/distance running (n = 35), dance (n = 32) and Australian football (n = 14). The distribution of sites of stress fractures varied from sport to sport. Among the track athletes (n = 54), navicular (n = 19), tibia (n = 14) and metatarsal (n = 9) were the most common stress fracture sites. The distance runners (n = 35) predominantly sustained tibia (n = 15), and fibula (n = 8) stress fractures, while metatarsal stress fractures (n = 18) were the most common among dancers. The distribution of sports varied with the site of the stress fracture. In the metatarsal stress fractures (n = 42), dance was the most common activity. Distance running (n = 15) and track (n = 14) were the most common sports in the group to have sustained tibia stress fractures (n = 36). Track athletes (n = 14) were particularly prevalent in the navicular stress fracture group (n = 26). The distribution of sites of stress fractures in this study shows some differences from previously published studies.

Prevalence of doping in sports: Doping control in Norway, 1977-1995

February 1998


32 Reads

To examine the results from doping controls conducted by the Norwegian Confederation of Sport (NCS) from 1977 to 1995. Data were collected by combining three computerized databases and manual records on samples taken and results from analyses in the International Olympic Committee (IOC)-accredited laboratories in London, Huddinge, Cologne, and Oslo. Samples were declared positive if they contained any banned substance on the IOC list that was in effect at any given time. A total of 15,208 samples were taken; most of them (12,870; 85%) were from Norwegian athletes (90% unannounced tests) belonging to national federations under NCS jurisdiction (NCS members), 461 (3%) were from external Norwegian athletes (either users of private gyms or athletes in organized sports federations not affiliated with the NCS), and 1,874 (12%) were from foreign athletes (three cases with unknown affiliation). There were 130 positive samples and 24 refusals among NCS members (1.2%; men, 1.4%; women, 0.3%), 86 positive samples and 8 refusals among external Norwegian athletes (20%; men, 24%; women, 8%), and 39 positive samples and 1 refusal among foreign athletes (1.6%; men, 2.1%; women, 0.7%). A gradual decrease in the percentage of positive samples was observed among NCS members as testing frequency was increased gradually from 1987 to 1995 in the three high-prevalence sports: powerlifting, weightlifting, and athletics. An increase in the test frequency of doping tests was associated with a decrease in the percentage of positive samples in targeted sports.

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