Risk Factors and Injury Mechanisms in Sports Injuries

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Original Editor - Wanda van Niekerk

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Introduction

Musculoskeletal injuries are common among athletes of all levels. The nature of these injuries vary among different sports, but the majority of these injuries are often as a result of a combination of factors and it is sometimes difficult to establish the specific mechanism that leads to injury. Epidemiological studies in sports show that the rate of injury in athletes varies from 10%-65% and for this reason, one of the main goals of sports physiotherapists and other professionals in sports is to prevent injury.A key step in evidence-based injury prevention is to identify possible risk factors for injury. Intrinsic risk factors such as strength, balance, joint mobility, biomechanics are often of interest as these are modifiable, whereas extrinsic risk factors such as age and previous injury are non-modifiable. Understanding modifiable risk factors is necessary for the design of effective targeted risk mitigation strategies.This may lead to the development of accurate and reliable tests to investigate risk factors, which is a necessary tool for athlete screening, monitoring of athletes over time and determine the efficacy of injury prevention programmes.

Risk Factors

Bahr and Krosshaug (2005) described risk factors for injury and mechanisms of injury. Internal risk factors that may predispose an athlete can include:

• Age
• Biological sex
• Body composition
• Health
• Physical fitness
• Anatomy
• Skill level
• Psychological factors

With the exposure to external risk factors, the athlete then becomes susceptible to injury. External risk factors include:

• Sports factors
• Protective equipment
• Environment

With the occurrence of an inciting event, the athlete is injured. Examples of inciting events are:

• Playing situation
• Player/opponent behaviour
• Gross biomechanical description (whole body)
• Detailed biomechanical description (joint)

Comprehensive model for injury causation designed by Bahr and Krosshaug

Meeuwisse et al (2007)[1]focused on the intrinsic and extrinsic risk factors for injury and developed a dynamic, recursive model of aetiology in sports injury. This injury prevention model from Meeuwisse et al (2007)[1] highlights the fact that “adaptations occur within the context of sport (both in the presence and absence of injury) that alter risk and affect aetiology in a dynamic, recursive fashion.”[1] It is suggested that one should look further than the initial risk factors preceding an injury and consider how these risk factors may have changed during various cycles of training or participation. (https://www.physio-pedia.com/Risk_Factors_and_Injury_Mechanisms_in_Sports_Injuries)

Add image form Meeuwisse 2007 with reference

It is evident that there are multiple factors involved in the risk of injury occurrence and the interaction between these factors may increase the risk. These factors are:

There are various factors that play a role in the risk of injury occurrence, and these factors can interact with each other:[13]

Training-related factors

Training volume, load, intensity

Type of training

Training and competition schedule

Rest

Motor control factors

Posture

Movement patterns

Muscle tone

Technique

Sport specific movements

Psychological factors

Beliefs

Fears

Coping strategies

Self-efficacy

Catastrophising

Emotional status (stress, depression, anxiety)

Health-related factors

Diet

Medication

General health

Fatigue

Sleep patterns

Non-modifiable factors

Gender

Age

Maturation stage

Body type

Genetics

Previous injuries

Environmental factors

Training/competition surface

Equipment

Clothing

Weather

Coaching

Conditioning factors

Strength

Endurance

Muscle length

Joint range of motion

Chronic capacity

Additional demands

Home

Work

Family

Social

Leadership

Media

Sponsors

Other factors

Sport specific skill level

Ranking and status

Goals of athlete – short- and long-term https://www.physio-pedia.com/Musculoskeletal_Injury_Risk_Screening)

Sports Injury Prevention Models

Van Mechelen Injury Prevention Model

Van Mechelen (1992) developed the fundamental, conceptual model for the prevention of sports injuries, which has since been developed and further adapted in relation to many sports and specific types of injuries. The four steps of action in this model are:

• Identification of the magnitude of the problem (prevalence and incidence of injuries)
• Identification of the cause and mechanism of injury
• Development and implementation of an injury prevention strategy
• Evaluation of the effectiveness of the intervention

Meeuwisse et al (2007)focused on the intrinsic and extrinsic risk factors for injury and developed a dynamic, recursive model of aetiology in sports injury. This injury prevention model from Meeuwisse et al (2007) highlights the fact that “adaptations occur within the context of sport (both in the presence and absence of injury) that alter risk and affect aetiology in a dynamic, recursive fashion.” It is suggested that one should look further than the initial risk factors preceding an injury and consider how these risk factors may have changed during various cycles of training or participation.

Dynamic model of etiology in sport injury

The TRIPP model by Finch (2006) considered the context of interventions and behavioral features of athletes and sports professionals.

Translating research into injury prevention practice (TRIPP) Framework

See also: Injury Prevention in Sport

Risk Factors and Injury Mechanisms

Injury Causation Model

Sports physiotherapists and other sports professionals recognise that the identification of the causes of injury is an important step in injury prevention as this can lead to the development of effective injury prevention programs. A model originally described by Meeuwisse (1994) and adapted and expanded upon by Barr and Krosshaug (2005) may guide sports professionals. It is important for sports professionals to know why certain athletes may be at risk of injury risk factors and how injuries occur (injury mechanism), in order to understand the causes of sports injuries. Sports injuries are rarely the result of a single factor, and can generally be attributed to an association of circumstances. Also, keep in mind that an athlete's risk of injury is not a constant and is likely to change over time.

Risk Factors

Risk factors can be divided into intrinsic and extrinsic risk factors as well as modifiable and non-modifiable factors.

Intrinsic Risk Factors

Internal risk factors can be modifiable or non-modifiable. Modifiable factors such as skill level or fitness levels may be addressed through specific training methods. Non-modifiable factors such as sex may be used to create target interventions for athlete populations at an increased risk (think about female athletes with an increased risk for ACL injuries) These internal risk factors may include:

• Age (maturation, ageing)
• Sex
• Body composition (e.g. body weight, fat mass, BMI, anthropometry)
• Fitness level (e.g. muscle strength/power, VO₂ max, joint ROM)
• Health (previous injury, joint instability)
• Anatomy (alignment, intercondylar notch width)
• Skill level (e.g. sports-specific technique, postural stability)
• Psychological factors (e.g. competitiveness, motivation, perception of risk)

Extrinsic Risk Factors

These factors include the external factors that athletes are exposed to and include:

• Human factors (e.g. teammates, opponents)
• Sports factors (e.g. coaching, rules, referees)
• Protective equipment (e.g. helmet, mouth guard, shin guards)
• Sports equipment (e.g. shoes, ski's, racquets)
• Environmental factors (e.g. weather, snow and ice conditions, floor and turf type, maintenance of playing surface)

Interaction between the intrinsic and extrinsic risk factors may cause an athlete to be more or less susceptible to injury. A combination of external and internal risk factors acting simultaneously puts an athlete at a higher risk for injury.

Injury Mechanisms

Injury mechanism can also be referred to as the “inciting event.” From a biomechanical perspective, considering tissue properties and load characteristics, an injury will be the result of the transfer of energy to tissue and the mechanical load will be in excess of the tissue's load tolerance. This is different for each type of tissue and is dependent on the type of load, the rate of load, the frequency of load and the magnitude of the load. Key points to remember when considering the biomechanical perspective is that biomechanics must explain how the injury is a result of mechanical load in excess of the tissue's loadbearing tolerance or how the mechanical load has reduced the tissue's tolerance level to a point where normal mechanical loads cannot be tolerated.

When considering an epidemiological model, load and load tolerance is influenced by the main elements of the model - the intrinsic risk factors, the extrinsic risk factors and the inciting event.

It is important to have a precise description of the injury mechanism or "inciting event". This information may be used to develop specific injury prevention measures for specific types of injuries and even for specific sports. The description of the injury mechanism may include information on different levels. These levels may include:

• Sports situation
  • team action
  • skills performed before and at point of injury
  • player position
  • court position
• Athlete behaviour
  • player performance
  • opponent interaction
• Whole body biomechanics
  • description of whole-body kinematics and kinetics
• Joint/tissue biomechanics
  • description of joint/tissue kinematics

Sports physiotherapists and sports professionals should know that each injury type has its typical patterns and the same for sports. Staying informed through keeping up with evidence-based literature is important for professionals working with athletes in all specific sports.