Musculoskeletal Injury Risk Screening

Original Editor - Wanda van Niekerk based on the course by Lee Herrington
Top Contributors - Wanda van Niekerk, Jess Bell, Kim Jackson, Tarina van der Stockt, Uchechukwu Chukwuemeka and Lucinda hampton

Introduction

Screening is a valuable process for athletes and is commonly practised in several elite sports. One of the common elements of a periodic medical assessment of athletes, is the musculoskeletal screening or examination. For many years, physiotherapists have screened athletes with the aim of identifying the athletes at risk for injury, so that they can then implement injury prevention programmes for these athletes. More recently, the focus has, however, shifted from using screening to predict injuries to rather using screening to identify possible predispositions to injury.

Reasons for the Periodic Medical Assessment of Athletes

The main reason for the periodic medical assessment of athletes is to safeguard sports participation, but there are many other additional benefits, including:

• Identification of medical conditions that contraindicate sports participation
• Assessment of known injuries and illnesses
• Review of current medications and supplements
• Athlete education
• Baseline testing
• Developing rapport with the athlete
• Specific screening
  • Cardiac screening
  • Screening for unknown illnesses
  • Screening for risk factors for future injury

Read more: Screening in sport and Pre-participation Screening

Why Screen for Injury Risk?

Injury rates in sports are increasing despite the increased professionalism of sports science and the use of sports medicine support teams. Although participation in sport is encouraged as part of a healthy lifestyle, the sport-related injury burden is high.

Consequences of Injuries in Sport

• Financial implications for the club
  • The cost of player injuries on sports leagues and organisations mainly fall into two categories: the direct medical costs and the opportunity cost of time loss injuries and shortened careers. This has led to professional teams offering players contracts contingent upon medical evaluations - players with high injury risk may then be offered short-term contracts.

• Team performance
  • A significant relationship between injury rates and time-loss with performance in elite team sports is reported.

• Financial implications for the healthcare system
  • Finch et al investigated the trends and burdens of hospital-treated sports injuries in Australia and estimated the direct cost of sport-related injury over 7 years to be $265 million Australian dollars.

• Financial costs for the individual
  • The inability to perform has a significant impact on an athlete’s earnings. Secrist et al showed that players in the National Football League with an ACL injury earned on average $2,070,521 less than salary-matched controls over the 4 years after the injury.
• Implications for long term health
  • It has been shown that knee injuries such as ACL or meniscal injury increase the odds of subsequently developing knee OA

• Career progression in sports
  • Larukain et al demonstrated a negative association between injuries and player progression in an elite football academy with players that progressed to the next level having a lower injury burden and higher match availability compared to players that did not progress.

Injury Prediction

Can we predict injuries? In literature, there is the issue of prediction or association. Most of the available literature looks at retrospective studies where an association between a certain physical factor and an injury is seen, as opposed to using a certain physical factor in a retrospective manner to investigate if it can actually predict an injury.

In recent years, much of the literature on screening tests suggests that these tests are not able to predict which athlete will sustain an injury, so clinicians are moving away from this idea. However, this does not mean that screening should not be performed, as "screening remains essential in our efforts to protect athletes’ health." The following video provides a good explanation on injury risk and screening.

An infographic explaining prediction versus association in sports injuries can be found here.

Factors Involved in the Development of Injuries

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

• 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

When considering injury screening, it is important to consider the myriad of factors that can influence injury occurrence. Furthermore, it is unlikely that these can be reduced to a single factor that may lead to injury. Factors that are commonly screened for in musculoskeletal injury risk screening are:

• Strength and conditioning
• Movement quality
• Stability/alignment

From the map by Bolling et al it is evident that these factors are just a few of the many factors that can be involved in injury occurrence.Athlete-related factors can also include background, technique, lifestyle. External factors can include: recovery time, equipment, social support, schedules. Preventative strategies can include: preparation and load management. See the map below for more detail and read the complete article: From the safety net to the injury prevention web: applying systems thinking to unravel injury prevention challenges and opportunities in Cirque du Soleil.

A multilevel system map with factors, strategies and stakeholders in relation to injury and its prevention. Starting at the centre of the map (ie, the athlete) and moving outwards; (A) entails artist-related intrinsic injury factors; (B) presents external injury factors; (C) describes the main preventive strategies (eg, load management, safety and preparation) which are driven by the factors from the inner two circles; (D) represents the stakeholders in the system as well as how they connect to the strategies and factors across the multiple levels.

Predisposition to Injuries

Instead of trying to predict injury occurrence, it may be more appropriate to identify athletes who are predisposed and where possible modify the predisposition.

• Non-modifiable predispositions include:
  • Anatomy
  • Genetics
  • Previous injury
  • Environmental factors

• Modifiable predispositions include:
  • Strength
  • Movement
  • Skill
  • Flexibility
  • State of the athlete e.g. tired or stressed?

This flow diagram created by Dr Lee Herrington illustrates how predispositions and exposure to load can lead to vulnerability in an athlete and, in combination with an inciting event, can lead to injury mechanisms and occurrences.

Injury predisposition

Considerations in Identifying Predisposed Athletes

• Understand the nature of the sport and the injuries occurring
  • Common injuries vs catastrophic injuries (for example hamstring injuries vs ACL injuries soccer)

• Identify which injury needs to be targeted as this will determine what type of screening tests will be used
• Do these specific injuries have modifiable factors?
• Are there clearly definable physical qualities related to the injury? Can these modifiable factors be clearly defined in terms of certain physical qualities?
• Can these physical qualities be identified with reliable screening tests?
• Can these physical qualities be influenced, modified or changed? (For example – blue eyes may be a predisposing factor to a certain type of injury and can easily and reliably be screened for, but eye colour cannot be changed, modified or influenced.)
• Traumatic injuries in the sport – how influenceable are traumatic injuries through screening and training?

Screening for Neuromuscular Control of Movement

Neuromuscular control is the ability to perform a movement in the best possible way to minimise loading stress or maximise the distribution of loading stresses on the tissue involved. An important part of “movement screening” is to identify the high-risk movement tasks and determine if these tasks can be broken down into closed skills.  A closed skill is undertaken in a controlled environment where the athlete only focuses on that specific skill (e.g. single leg squat or single-leg landing). An open skill is undertaken in a very chaotic and random environment (e.g. single-leg landing in the middle of a sporting environment such as competition or match). The context in which these movements take pace will have an influence on performance, as well as the risk for injury. For example, an athlete may pass a closed skill test/task such as single-leg landing at the pre-season screening, but still get injured (i.e. ACL injury) as a result of a single-leg landing in a sporting environment such as a competition.

Selecting a Screening Test/Task

Factors to consider when selecting a screening test or task include:

• Nature of activities undertaken in the specific sport
• Nature of the major injuries in the specific sport (are these linked to specific movements or activities?)
• Athlete’s injury history (can previous injuries be linked to specific movements or activities?)

Factors Influencing Neuromuscular Control of Movement

Various factors can have an impact on an athlete's ability to perform a specific screening test or task. These include:

• Strength
• Joint range of motion
• Muscle length – flexibility
• Proprioception – joint position sense
• Movement dissociation
• Sport specific skill

Building a Paradigm for Injury Risk Screening

• Consider predisposition versus prediction of injuries
  • Screening tests cannot predict if an athlete will get injured, but we can screen and look for predisposed athletes. Remember that being predisposed to a certain injury does not mean that an athlete will get injured. Also, if an athlete does not have a predisposition to an injury, this is not a guarantee that the athlete will not be injured. Athletes become vulnerable to injury when they are exposed to load and inciting events (see flow diagram above).

• Identify if force generation, force absorption or movement skill are an issue in predisposition
• Identify the predisposing movement task/s
• Break down the identified movement task into closed skills that can be measured reliably
• If the athlete fails the test/task, identify the reasons for failure
• Build ways to improve the skill in a controlled environment, but then also in training and competition environments

Examples of Screening Tests

• Lower quadrant tests
  • Single-leg squat
  • Single-leg landing
  • Drop jump Test
  • Star Excursion Balance Test
  • Hop for distance tests

• Upper quadrant tests
  • Glenohumeral Internal Rotation Deficit (GIRD)
  • Closed chain upper limb test

• Functional Movement Screen (FMS)
• United States Tennis Association High Performance Profile
• Nine Test Screening Battery
• Athletic Ability Assessment
• Boksmart pre-participation screening of players
  • This website has various documents that can be downloaded such as the musculoskeletal assessment form and protocol as well as various other assessment documents.

Resources

• Risk factors and injury mechanisms in sports injuries
• Rod Whiteley, Sports Physiotherapist. Aspetar. If screening is a waste of time as Roald Bahr tells us, why should you still be doing it?
• Below are two videos you can watch on injury risk screening