When is a muscle strain not a muscle strain? A new study in the British Journal of Sports Medicine highlights that athletes who strain their hamstring muscles may need closer attention from the medical and training staff then we previously thought.

Most “muscle sprains” in athletes are reported first to the head trainer in a sports team or gym. The magnitude of these injuries are often underestimated by athletic trainers and the athletes likewise put a lot of trust into their trainers.

Why do some muscle injuries such as  hamstring and quadriceps strains take much longer to heal than others? Which injuries are more prone to recurrence? Intramuscular tendon injuries have received little attention and are often just thought of a ‘muscle strain’. In thigh muscles, such as rectus femoris and biceps femoris, the attached tendons extend for a good distance within the muscle belly. While, most injuries actually occur at the area called the musculo-tendinous junction, this study is telling us to pay attention more closely because the injury could be in fact in the muscle belly or a detachment of the tendon itself. Most hamstring injuries present with pain within a muscle belly. In addition to the musculo-tendinous injury being a site of pathology, the intramuscular tendon itself is occasionally injured. These injuries have a variety of appearances on MRIs. There is some evidence that these injuries require a prolonged rehabilitation time and may have higher recurrence rates. Therefore, it is important to recognize the tendon component of a thigh “muscle strain.”

This group found that injuries involving the quadriceps or hamstring tendons have prolonged rehabilitation and return to play times and that they must be treated differently than muscle strains. If an injury to the tendons is suspected, an MRI is indicated for accurate diagnosis. Improved recognition of injury of the intramuscular tendon may allow more accurate prediction time and help judge when the athlete is ready to return to play. This will also reduce the risk of recurrent injuries. Finally the role of surgical repair versus conservative management in these types of injuries is not completely clear. The options need to be weighed carefully by a competent medical team. But what is clear is that when the tendon is torn, long term outcome is greatly affected by the decision of surgical versus conservative care.

Br J Sports Med 2016;50:205-208 doi:10.1136/bjsports-2015-095136