11 Nov The curse of hamstring injuries: can we prevent it?
Hamstring injuries are one of the most occurring muscle injuries in team sports. In football, 37% of all muscle injuries are hamstring injuries. A hamstring injury is characterized by a relatively long recovery period (4-8 weeks) and a high recurrence rate of up to 33%. These factors together show the important of preventing hamstring injuries in the first place. Therefore, in this blog we will provide guidelines which can help you to reduce the incidence of hamstring injuries in your team.
High-speed running activities are named as the common cause of hamstring injuries. The occurrence of hamstring injuries is caused by a failure of the muscles to tolerate the high forces during these actions. In the English Premier League, it has been shown that the incidence of hamstring injuries peaks around November-January. Traditionally, this period has a busy match schedule and, in contrast to other competitions, does not have a winter break. However, competitions with a winter break, have a higher incidence of hamstring injuries towards the end of the season. This is the period when there may be a decreased focus on physical fitness, with an increased focus on match results. These outcomes highlight that training schedules with a gradual increase in load (i.e. avoiding peaks in load by building a high ‘chronic’ load) and a balance between exercise and rest will decrease the incidence of hamstring injuries.
However, the mechanisms of muscle injuries are too complex to state that a balanced training program will prevent all hamstring injuries. Since hamstring muscle strength has been shown as a risk factor for hamstring injuries, improving (eccentric) hamstring strength might reduce the incidence of these injuries. The Nordic Hamstring Exercise (see image), has been shown to be an effective tool for improving eccentric hamstring strength. Furthermore, research has shown that integrating this exercise in a training program has reduced hamstring injuries! This reduction in injury incidence is believed to be partly explained by the improved hamstring strength. However, the precise mechanisms behind this reduction are still unclear.
Even though the Nordic Hamstring Exercise has been effective in reducing hamstring injuries, adherence to a training program that systematically includes this exercise is low (<20%). The relatively high levels of muscle soreness after this exercise, party account for this low adherence. Furthermore, high volumes of this exercise (up to 100 repetitions in a week), are thought to decrease the adherence to such a program as well. However, lower volumes of the Nordic Hamstring Exercise (2 times a week, 4 sets of 2 repetitions) have also been found to be effective for improving hamstring muscle strength. Therefore, such a lower volume Nordic Hamstring Exercise program might improve adherence to the program and, in succession, might reduce the incidence of hamstring injuries.
Hamstring injuries are one of the most occurring muscle injuries in team sports. Reducing the incidence of this injury can be achieved via a balanced training program: a gradual increase in load over time and the right balance between exercise and rest. However, the mechanisms behind this injury are too complex to state that you are able to prevent all hamstring injuries via a balanced periodization schedule. Therefore, the Nordic Hamstring Exercise can be added to a training program to further reduce the number of hamstring injuries. This exercise has been found to improve the eccentric hamstring muscle strength and, in succession, decrease the incidence of these injuries by up to 50%. However, the adherence to such a program is often low due to relatively high levels of muscle soreness associated with it, and the high volume of the program. Hence, if one wants to successfully implement this exercise in a training program, lower volumes are advised.