Introduction
Joint hypermobility (JH) is an extremely heritable condition in which the joints have a range of motion beyond normal limits.1 The prevalence of hypermobility declines with age, falling from 34% in those aged 20–30 years to 18.4% in those aged 60 years or older.2 The prevalence is greater in women than in men, and a 2:1 ratio is generally observed.3 JH is a condition that is seen frequently in healthy individuals who do not have complaints. It is important to differentiate this from joint hypermobility syndrome, which is a recognised rheumatological condition that arises when a hypermobile joint is associated with arthralgia, soft tissue injury or joint instability.4 Hypermobility is diagnosed as a Beighton score of 4 or above.5
Inherent hypermobility can attract individuals to certain sports, as activities are easier to perform. However, it can also carry some disadvantages as the rates of injury in certain sports are shown to be higher.6
Anecdotal evidence suggests that being hypermobile increases the likelihood of sustaining injury in contact sports, while it may prevent injury in non-contact sports. This may be because hypermobile joints are unstable in nature due to their increased range of movement and subsequently reduced core stability. Subsequently, when impact occurs, they are not able to direct the force through the joint in a stable manner. In contact sports this causes joints to be in unstable positions due to their hypermobile nature, and when exposed to physical contact leads to injury. One may also hypothesise that JH may prevent injury in sports that require increased flexibility as there is less stress put through an already flexible joint. An example that highlights this is that if a runner misplaces their footing a flexible joint is able to move to the desired direction without sustaining injury. However, in a less flexible joint, an injury may occur. Hypermobile individuals may also be attracted to certain sports that require increased flexibility as certain movements are easier to perform, for example, hypermobility and being a gymnast.7 It has also been suggested that training can increase flexibility.
Beighton score
The Beighton score is an edited version of the Carter-Wilkinson scoring system, which was used as an indicator of widespread hypermobility. A Beighton score is a useful research tool to indicate generalised hypermobility. It is straightforward to perform clinically, but a high Beighton score does not mean an individual has hypermobility syndrome. Signs and symptoms also need to be present before hypermobility syndrome can be diagnosed.8 Likewise, a low score should be considered with caution as hypermobility can present as chronic pain in joints that are not assessed by the Beighton score, for example, neck, jaw, back or shoulder pain.9 Medical professionals vary in their interpretation of the results, with some accepting as low as 1 out of 9 as being hypermobile. The general consensus is that a score of 4 or more defines hypermobility.10
Literature review
A literature search was conducted using PubMed, CumulativeIndex to Nursing and Allied Health Literature, Medline and Google Scholar. The search terms set were ‘hypermobility’, ‘sport’ and ‘injury’, and only peer-reviewed journals were included in the results. In addition, only papers from year 2000 and those that were published in English were selected. Abstracts were not included in the search results.
There does not appear to be a clear consensus that identifies an association between hypermobility and sports injury. Some papers suggest there is one; however, there is limited statistical evidence to support the finding.7 11–14 Other papers suggest that being hypermobile may prevent injury in certain sports.9 11 15 16 Most research finds no association at all.15 17 18 Most papers analysed a single sport.
Pilot study and focus group
A small-scale pilot study and focus group was performed before commencement of data collection. There were two aims: the first was to identify whether the questionnaires designed asked appropriate questions and were clear in the instruction (this was fed back through the focus group), and the second was to determine whether the results can be analysed using the appropriate statistical test. The focus group provided an insight into how individuals thought and provided a deeper understanding of the area being studied. Focus groups can also be used for feedback and integration of a study design.19