The effect of anthropometric parameters, biomechanical malalignments and flexibility of the lower extremities on the prevalence of Medial Tibial Stress Syndrome in rugby players of the North–West University Rugby Institute

Abstract

With the general increase in Rugby union's popularity the past decade, there has been an increase in sport injuries, both from acute and overuse trauma. Approximately half of all sport injuries may be attributed to overuse or repetitive micro trauma rather than a single traumatic event. Although very few overuse injuries have an established aetiology, the fact that over 80% of these injuries occurs at or below the knee suggests that there may be some common mechanisms in the aetiology. It could only be stated with certainty that the aetiology of these injuries is multifactorial and diverse, with both extrinsic and intrinsic factors contributing. Many intrinsic factors (personal) predispose athletes to develop overuse injuries. Intervention of intrinsic injury risk factors is more problematic, as intrinsic risk factors are often difficult to examine and even more difficult to rehabilitate than external factors. Extrinsic risk factors (environmental) that are independent of the injured person can be influenced through the intervention of the extrinsic factors. Main attention should be paid not to the treatment of the site of injury but to the possible cause of the symptoms. It is therefore vital that coaches and medical teams have a complete understanding of the incidence, nature, severity, and causes of injuries in order to review the adequacy of their injury prevention, treatment and rehabilitation. The objectives of this study were to determine the effect of selected anthropometric parameters, biomechanical malalignment and flexibility on the prevalence of Medial tibial stress syndrome (MTSS) in U/19 university rugby players of the 2006 season of the North-West University (NWU) Rugby Institute (RI). A prospective once-off subject availability study was performed that included U/19 rugby union players of the RI of the NWU (n=91). Selected biomechanical and anthropometrical assessments were made. Biomechanical and anthropometrical assessments were preformed on all subjects before the start of the season. All existing injuries were recorded by means of an injury history questionnaire. Descriptive statistics (e.g. mean and standard deviations) and contingency tables were used to analyse the data. Effect sizes were used to decide on the practical significance of the findings. A cut-off point of 0.8 (large effect) was set for practical significance of differences between means. Players with MTSS had a wider Bi-iliocristal width than those without MTSS. There were leg length differences for both players with and without MTSS for Hiospinale, Trochanterion-Tibiale lateral and Tibial lateral length. Iliospinale- and Trochanterion-Tibiale lateral length differences presented with the largest length difference. Iliospinale, Trochanterion-Tibiale lateral and Tibial lateral length difference had a small effect. Only Bi-iliocristal width presented with a medium effect. Hamstrings, Gastrocnemius and Plantaris as well as Soleus and Popliteus flexibility of players without MTSS were tighter than those of players who suffered from MTSS. Only Hamstring tightness had a small effect. Gastrocnemius and Plantaris as well as Soleus and Popliteus presented with a medium effect. Players without MTSS had a more flexible TFL on their right side. All the other flexibility measurements of the Thomas test presented that players without MTSS had a more inflexible profile. Effect size was not analysed because of the small sample sizes in some of the cells. Players without MTSS presented with an overall more inflexible profile than those with MTSS. More players without MTSS supinated at heel contact on both their feet, compared to the players with MTSS. Players without MTSS supinated more on both their feet during mid stance. A small percentage of players with and without MTSS supinated during the propulsion phase. More players without MTSS had a neutral right foot mid stance compared to players with MTSS who had a more neutral mid stance on their right foot. Players with MTSS pronated more with both their feet during propulsion. Players with MTSS pronated mostly during the propulsion phase and mostly had flatter and higher arched feet than players without MTSS. More players with MTSS had a light flat foot, flat foot as well as a high arched foot than players without MTSS. Most of the players with MTSS had normal right arched foot type. None of the players with MTSS had either a light high right foot or a high arched left foot.