The prevalence of chronic knee injury in triathletes

A Systematic Review of Long‐Distance Triathlon Musculoskeletal Injuries

The distribution of injuries affecting long-distance triathletes is yet to be fully understood. A systematic review was performed of the clinical literature to determine the epidemiology of musculoskeletal injuries affecting long-distance triathletes. Searched databases in Feb 2020 were PubMed, Medline, EMBASE, EMCARE, and CINHAL databases. Published observational research articles related to the incidence or prevalence of musculoskeletal injuries in long-distance triathletes (competing at “Ironman” full distance or greater), written in the English language and not restricted by age or gender or date were eligible. Of the 975 studies identified on the initial search, six studies met the inclusion criteria for analysis. The mean age (SD) of the long-distance triathletes in these studies was 35.1 (2.7) and the range was 21-68 years. Overuse injuries were most frequent with the incidence range of 37-91%, and acute injury incidence range was 24-27%. The knee and spine were the most frequent location of injury. Running and cycling were the most frequently affected disciplines. Elite athletes had a lower incidence of overuse injury (37%). The highest acute injury incidence (27%) was recorded in non-elite athletes. The quality of the studies was relatively poor with only one study satisfying >50% of the quality assessment tool questions and only two studies were prospective, the rest were retrospective cross-sectional studies. Overall, there is a lack of literature reporting on musculoskeletal injuries in long-distance triathletes. Overuse injuries, particularly in the knee, are the most frequently reported, running and cycling are the most frequent disciplines associated. Long-distance triathletes may have a lower incidence of both overuse and acute injuries.

A Random Forest Machine Learning Framework to Reduce Running Injuries in Young Triathletes

Background: The running segment of a triathlon produces 70% of the lower limb injuries. Previous research has shown a clear association between kinematic patterns and specific injuries during running. Methods: After completing a seven-month gait retraining program, a questionnaire was used to assess 19 triathletes for the incidence of injuries. They were also biomechanically analyzed at the beginning and end of the program while running at a speed of 90% of their maximum aerobic speed (MAS) using surface sensor dynamic electromyography and kinematic analysis. We used classification tree (random forest) techniques from the field of artificial intelligence to identify linear and non-linear relationships between different biomechanical patterns and injuries to identify which styles best prevent injuries. Results: Fewer injuries occurred after completing the program, with athletes showing less pelvic fall and greater activation in gluteus medius during the first phase of the float phase, with increased trunk extension, knee flexion, and decreased ankle dorsiflexion during the initial contact with the ground. Conclusions: The triathletes who had suffered the most injuries ran with increased pelvic drop and less activation in gluteus medius during the first phase of the float phase. Contralateral pelvic drop seems to be an important variable in the incidence of injuries in young triathletes.

Risk factors for acute injuries and overuse syndromes of the shoulder in amateur triathletes - A retrospective analysis

Objectives

To investigate the prevalence of shoulder-related acute and overuse injuries in triathletes and examine the role of possible risk factors, in order to identify potential preventive measures.

Methods

We performed a retrospective epidemiologic study of 193 amateur triathletes between June and August 2013 and evaluated their competition and training habits, as well as the presence of acute and overuse injuries of the shoulder sustained during the past 12 months. Contingency tables were analyzed using Pearson’s chi-squared test. Normally distributed data were compared with the independent samples t-test, while non-parametric analyses were performed with the Mann-Whitney U test. Binary logistic regression was used to identify important predictors of injuries.

Results

12 participants (6%) sustained acute injuries and 36 athletes experienced an overuse injury. The acute injury rate amounted to 0.11 per 1000 hours of training and the overuse injury rate to 0.33 per 1000 hours of training. There was no association between athletes’ age, height, weight, BMI, a history of shoulder complaints or triathlon experience in years and acute or overuse injuries. Male athletes had a trend for sustaining more acute injuries then female athletes (8% vs. 2%, p = 0.079). Athletes with acute injuries spent a significantly higher amount of time per week doing weight training (p = 0.007) and had a trend for a higher weekly duration of cycling training (p = 0.088). Athletes with overuse injuries participated in a significantly higher number of races compared to athletes without overuse injuries (p = 0.005). The regular use of paddles was associated with a significantly higher rate of overuse injuries (24% vs. 10%, p = 0.014).

Conclusion

The regular use of paddles during swimming training appears to be a risk factor for the development of overuse injuries, while an increased duration of weight and cycling training seems to be associated with a higher rate of acute injuries.

The impact of triathlon training and racing on athletes' general health

Although the sport of triathlon provides an opportunity to research the effect of multi-disciplinary exercise on health across the lifespan, much remains to be done. The literature has failed to consistently or adequately report subject age group, sex, ability level, and/or event-distance specialization. The demands of training and racing are relatively unquantified. Multiple definitions and reporting methods for injury and illness have been implemented. In general, risk factors for maladaptation have not been well-described. The data thus far collected indicate that the sport of triathlon is relatively safe for the well-prepared, well-supplied athlete. Most injuries 'causing cessation or reduction of training or seeking of medical aid' are not serious. However, as the extent to which they recur may be high and is undocumented, injury outcome is unclear. The sudden death rate for competition is 1.5 (0.9-2.5) [mostly swim-related] occurrences for every 100,000 participations. The sudden death rate is unknown for training, although stroke risk may be increased, in the long-term, in genetically susceptible athletes. During heavy training and up to 5 days post-competition, host protection against pathogens may also be compromised. The incidence of illness seems low, but its outcome is unclear. More prospective investigation of the immunological, oxidative stress-related and cardiovascular effects of triathlon training and competition is warranted. Training diaries may prove to be a promising method of monitoring negative adaptation and its potential risk factors. More longitudinal, medical-tent-based studies of the aetiology and treatment demands of race-related injury and illness are needed.

Treatment of lateral knee pain using soft tissue mobilization in four female triathletes

STUDY DESIGN

Prospective case series.

BACKGROUND

These case reports present results of the treatment of lateral knee pain in four female amateur triathletes. The athletes were referred to the author's clinic with either a diagnosis of iliotibial band friction syndrome or patellofemoral pain syndrome, all four having symptoms for longer than seven months. Changes in training routines were identified as the possible cause of the overuse injuries that eventually developed into chronic conditions.

INTERVENTION

Treatment involved soft tissue mobilization of the musculotendinous structures on the lateral aspect of the knee.

RESULTS

At four weeks, three of the athletes improved 9 to 19 points on the Lower Extremity Functional Scale, 3 to 5 points on the Global Rating of Change Scale, and demonstrated improvement in hamstring and iliotibial band flexibility. At eight weeks the Global Rating of Change for these three athletes was a 7 ("a very great deal better") and they had returned to triathlon training with no complaints of lateral knee pain. One athlete did not respond to treatment and eventually underwent arthroscopic surgery for debridement of a lateral meniscus tear.

CONCLUSIONS

After ruling out common causes for lateral knee pain such as lateral meniscus tear, lateral collateral ligament sprain, patellofemoral dysfunction, osteochondral injury, biceps femoris tendonitis, iliotibial band friction syndrome or osteoarthritis, soft tissue restriction should be considered a potential source of dysfunction. In some cases soft tissue restriction is overlooked; athletes go undiagnosed and are limited from sports participation.

Chronic musculoskeletal conditions associated with the cycling segment of the triathlon; prevention and treatment with an emphasis on proper bicycle fitting

Cycling-related injuries account for 20% of all injuries occurring during triathlons. Traumatic injuries caused by falls or accidents are thankfully rare but can be highly variable and very serious in nature. The best approach to these injuries is prevention. The majority of complaints arising from cycling are due to overuse or poor technique. The knee joint, lower back, neck, and Achilles tendon are the most frequently affected anatomic sites. Anterior knee pain, lower back and neck myofascial pain, iliotibial band friction syndrome, and Achilles tendonitis are the most common diagnoses. Initial treatment should always use rest, ice, compression, and elevation. Muscle strengthening and stretching as well as other physical modalities are helpful in the subacute setting. The need for surgery is rare. Improper bike fit contributes to the causation of a significant number of these conditions. Bike geometry may also be altered to alleviate symptoms.

Imaging of triathlon injuries

Injuries in triathletes are common and are mostly overuse injuries. Rotator cuff tendinitis is the most common complaint from swimming, but the incidence of tendinopathy and rotator cuff tears on magnetic resonance imaging is comparable in triathletes without and with shoulder pain. Cycling injuries are mainly to the knee, including patellar tendinosis, iliotibial band syndrome, and patellofemoral stress syndrome, and to the Achilles tendon and the cervical and lumbar spine. Running is associated with most injuries in triathletes, during both training and racing, causing the athlete to discontinue the triathlon. In addition to knee injuries from running, triathletes may also develop foot and ankle, lower leg, and hip injuries similar to single-sport distance runners. Some injuries in triathletes may be mainly symptomatic during one of the three sports but are exacerbated by one or both of the other disciplines.

A profile of injuries in athletes seeking treatment during a triathlon race series

BACKGROUND

Triathlon combines swimming, cycling, and running into a single event. With increasing popularity of this sport, there has been a rise in the number of participants, particularly in shorter distance races. However, the risks of participating in short-distance races have not been reported.

PURPOSE

To describe the rate and profile of injuries seen for medical assistance during a triathlon race series.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

A standardized injury reporting form was used to collect information from race entrants seeking medical aid at each of the races comprising a combination of Sprint, Olympic, and Fun race distances in a triathlon series in Victoria, Australia over the 2006-2007 race season. Injury rates and risk factors were assessed via regression analysis.

RESULTS

There were 10,197 individual starters who took part. There were 235 presentations for medical assistance (n = 322 injuries) over the series. The presentation rate was 20.1 per 1000 hours of competition (2.3% of total race starts). Injuries were predominantly sustained during the run (38.4%) and cycle (14.3%) legs. Lower limb injuries (59.5%) and abrasions (28.6%) were the most common site and nature of injury, respectively. There were 9 severe injuries: 5 fractures, 3 probable heat stroke cases, and 1 deep laceration. Elite/Junior Elite, Olympic distance, and 12- to 19-year-old competitors were at higher risk of injury, especially during running and cycling.

CONCLUSION

The level and age of triathlon competitors, and the race distance, influenced the risk of injury over a race series. These results provide timely information for triathlon race event organizers and could be incorporated into a review of practices for the provision of medical services to triathlon events, especially the common sprint distance competitions.

CLINICAL RELEVANCE

Shorter distance triathlons have lower injury rates and relatively minor injuries, but medical teams and race organizers should be prepared for serious injuries.

The influence of abnormal hip mechanics on knee injury: a biomechanical perspective

During the last decade, there has been a growing body of literature suggesting that proximal factors may play a contributory role with respect to knee injuries. A review of the biomechanical and clinical studies in this area indicated that impaired muscular control of the hip, pelvis, and trunk can affect tibiofemoral and patellofemoral joint kinematics and kinetics in multiple planes. In particular, there is evidence that motion impairments at the hip may underlie injuries such as anterior cruciate ligament tears, iliotibial band syndrome, and patellofemoral joint pain. In addition, the literature suggests that females may be more disposed to proximal influences than males. Based on the evidence presented as part of this clinical commentary, it can be argued that interventions which address proximal impairments may be beneficial for patients who present with various knee conditions. More specifically, a biomechanical argument can be made for the incorporation of pelvis and trunk stability, as well as dynamic hip joint control, into the design of knee rehabilitation programs.

LEVEL OF EVIDENCE

Aetiology/therapy, level 5.

Triathlon related musculoskeletal injuries: The status of injury prevention knowledge

Triathlon is a popular participation sport that combines swimming, cycling and running into a single event. A number of studies have investigated the incidence of injury, profile of injuries sustained and factors contributing to triathlon injury. This paper summarises the published literature in the context of the evidence base for the prevention of triathlon related injuries. Relevant articles on triathlon injuries were sourced from peer-reviewed English language journals and assessed using the Translating Research into Injury Prevention Practice (TRIPP) framework. This review highlights the significant knowledge gap that exists in the published literature describing the incidence of injury, the profile of injuries sustained and evidence for the prevention of injury in triathlon. Despite the number of studies undertaken to address TRIPP Stages 1 and 2 (injury surveillance, aetiology and mechanism of injury), most triathlon studies have been limited by retrospective designs with substantial, and unvalidated, recall periods, inconsistency in the definitions used for a reportable injury and exposure to injury, or a failure to capture exposure data at all. Overall, the paucity of quality, prospective studies investigating the incidence of injury in triathlon and factors contributing to their occurrence has led to an inability to adequately inform the development of injury prevention strategies (TRIPP Stages 3-6) for this sport, a situation that must be rectified if gains are to be made in reducing the burden of triathlon related injury.

Epidemiology of athletic knee injuries: A 10-year study

The knee is an anatomically and biomechanically complex joint. Few studies have been published reporting the type and frequency of knee injuries. However, this information that may help to prevent, diagnose, and treat knee joint injuries. We have documented 17,397 patients with 19,530 sport injuries over a 10-year period of time. 6434 patients (37%) had 7769 injuries (39.8%) related to the knee joint. 68.1% of those patients were men and 31.6% were women. Almost 50% of the patients were between the ages of 20-29 (43.1%) at the time of injury. The injuries documented were ACL lesion (20.3%), medial meniscus lesion (10.8%), lateral meniscus lesion (3.7%), MCL lesion (7.9%), LCL lesion (1.1%), and PCL lesion (0.65%). The activities leading to most injuries were soccer (35%) and skiing (26%). LCL injury was associated with tennis and gymnastics, MCL with judo and skiing, ACL with handball and volleyball, PCL with handball, lateral meniscus with gymnastics and dancing, and medial meniscus with tennis and jogging.

Knees of Ironman triathletes: magnetic resonance imaging assessment of older (>35 years old) competitors

PURPOSE

To use magnetic resonance imaging (MRI) to evaluate the knees of older (>35 years old), competitive Ironman triathletes to determine the prevalence of abnormal findings.

MATERIALS AND METHODS

The knees of 29 Ironman triathletes (20 men, 9 women; age range, 35-66 years old) were studied by MRI. The findings were analyzed collectively and categorized into group I (N = 13), subjects without prior knee injuries and symptoms, and group II (N = 16), subjects with prior knee injuries and/or current symptoms.

RESULTS

Ten percent of the knees had ligamentous abnormalities, but the prevalence was not statistically different comparing group I to group II. Fifty-five percent had abnormal menisci. The overall prevalence of abnormal menisci was significantly higher in group II (69%) than in group I (38%, P < 0.05). Cartilage abnormalities were found in 21% of the triathletes with a higher prevalence in group II (31%) than in group I (8%, P < 0.05). Twenty-one percent (6/29) of the knees had bone contusions, with a higher prevalence in group II (31%) than in group I (8%, P < 0.05).

CONCLUSION

In general, the spectrum of abnormal MRI findings of the knee was no greater than age-related changes previously reported for other athletic populations and nonathletes. These results have important implications for the diagnostic use of MRI of the knee in this high-endurance, athletic population.

Triathlon

The aim of this study was to determine the effect of prior cycling on EMG activity of selected lower leg muscles during running. Ten elite level triathletes underwent two testing sessions at race pace: a 40 km cycle followed by a 2 km run (CR) and a 10 km run followed by a 2 km run (RR). EMG data from selected lower limb muscles were collected at three sections of each run (0 km, 1 km and 2 km) for six strides using a portable data logger. Significant differences (p < 0.05) between condition were found for the level of activation (Lact) for biceps femoris (BF) during stance and vastus lateralis (VL) during flight and stance. Vastus medialis (VM) changed in Lact, during flight, between sections in the 2 km run. Furthermore, significant differences (p < 0.05) between condition were found for BF during stance and for rectus femoris (RF) and VM during flight. There was a significant difference (p < 0.05) in the duration of VL activation (Dact) across sections of the 2 km run. Findings from this investigation highlight changes in muscle function when changing from cycling to running and indicate a need to train specifically for the cycle to run transition. Such training may improve performance and reduce the risk of injury.