It does not take a professional eye to take notice of the frequency of hamstring injuries in sport. Evaluating the injury list for collegiate and professional teams, you will find that hamstring injuries are at the top of non-contact related sport injuries. Even more staggering is that roughly 1/3 of all hamstring injuries will recur, with the majority recurring within the first 2 weeks. Now these statistics mainly reflect sports which involve sprinting, however hamstring issues can create problems for athletes regardless of sport. It is important to understand that hamstring health becomes more critical as increasing loads and demands are placed on them. Given these statistics, one can logically bring into questions if traditional return to play guidelines and rehabilitation programs are truly ideal.
A quick look at the picture above and it becomes clear the hamstring is actually the collection of four muscles. The semimembranosus (SM), semitendinosus (ST), bicep femoris long head (BFLH), and bicep femoris short head (BFSH). Understand that three of the hamstrings are biarticular (SM, ST, and BFLH). This means they are 'two-jointed' and cross the knee and hip, thus influencing both knee and hip movements. The two primary actions the hamstring produces are hip extension (except for BFSH) and knee flexion (all 4). This brief overview of the hamstrings has implications as to the how and the why behind hamstring treatment, rehab, and training.
The act of 'pulling' a hamstring usually occurs at high speed running during the terminal swing phase of the gait cycle. In the picture above, this phase is seen in the athlete's right leg. As the hip is decelerating the forceful momentum as the leg swings forward, the hamstrings are loaded and lengthening as you are finishing the swing phase before foot strike. There are predisposing factors that ultimately cause the hamstring to be compromised such as: poor neuromuscular control or the lumbopelvic region, asymmetries in muscle length and/or hip range of motion, and sacroiliac joint dysfunction. All of these factors need to be and should be considered when devising a treatment and rehab protocol to ultimately reduce the risk of re-injury.
The GP Approach
Effective treatment for a hamstring strain, and for any injury, must address not only the site of pain but ALL possible predisposing factors. As stated above, there are essentially three 'reasons' as to why hamstring injuries occur. Sprinting is not the problem. Focusing on each predisposing factor through progressive treatment and training will best prepare the athlete for return to sport activities.
The utilization of manipulation, massage, soft tissue techniques, and nutritional considerations to support tissue healing become the foundation of early care and recovery from hamstring injury. Everything used to facilitate healing is based on examination and identification of the presence of any predisposing factor(s).
The transition from rehabilitation to return to sport then becomes dependent upon a process that addresses proper tissue healing and exercise progressions to improve structural balance, lumbopelvic control, strength, and coordination of movement required by sport specific demands in output and movement patterns.