Written by Team Juggernaut
Jason M. Reynolds DC, DACBSP, EMT
If you were to check the Disabled List, Injured Reserve or track the injury history of any amateur or professional athlete, you would find that hamstring injuries are at the top of all non-contact sporting injuries at any level of competition. What’s staggering is that ~1/3 of all hamstring injuries will recur, most of which recur within the first 2 weeks. It is evident that return to play guidelines and the rehabilitation programs that have traditionally been utilized are not ideal. These stats of course are mainly true of sports requiring sprinting, and a triple extension movement pattern. However anybody can have hamstring woes regardless of the sporting need, it just makes it that much more vital in dry land sprinting athletes. So regardless of your sport or activity, a hamstring that is not pulling its weight can cause you a lot of grief and unanswered questions.
The hamstring is actually the collection of 4 muscles. The semimembranosus, and semitendinosus are the more medial muscles and have synergistic movements with the nearby adductor musculature. The biceps femoris has a long head and a short head and they the more lateral muscles. All musculature has an origin on the ischial tuberosity of the pelvis except the short head of the biceps femoris, which has an origin on the femur itself. The 2 medial hamstrings attach on the tibia, where the 2 lateral hamstrings attach on the fibular head. All muscles are innervated by the L5 (fifth lumbar) and S1 (first Sacral) Nerve roots which combine to comprise the Sciatic nerve. However, the peripheral nerve that innervates the short head of the biceps femoris is the common peroneal. The other 3 hamstrings have a peripheral innervation from the tibial branch of the sciatic nerve. The action the hamstring produces is hip extension (except for Short head biceps femoris), as well as knee flexion (all 4). This mundane grade school review of the hamstrings actually has huge implications as to how and why we traeat, rehab and train the hamstring musculature the way we do.
In general a muscles integrity is compromised with excessive eccentric loads at high velocities. The act of “pulling” a hamstring usually occurs at high speed running during the terminal swing phase of the gait cycle. As your hip is decelerating the forceful momentum of your leg coming forward your hamstrings are loaded and lengthening as you are finishing the swing phase. This combination velocity and tension most times then not results in a strain of the hamstring in the belly of the muscle. In other sports such as dancing the extreme ranges of hip flexion add stress to the proximal origin at the ischial tuberosity and involve the tendon and can sometimes involve the bone and prolong recovery. These kinematics of injury are often times the straw on the camels back. There are predisposing factors that ultimately cause the hamstring to be compromised during one of these kinematic injury mechanisms. Some predisposing factors in the hamstrings inability to withstand either extreme in the length tension curve with sprinting or excessive flexion hip range of motion can be a combination of the following: Poor lumbopelvic control, asymmetry in muscle length and hip range of motion, Sacroiliac dysfunction, and neuromuscular control issues. These are a few important factors that have been found in the literature. All of these factors need to be considered when devising a treatment and rehab protocol. Neglecting one of these factors will result in recurrence of the proverbial hamstring injury.
The “Paradigm” Approach:
All treatment protocols for a hamstring strain, and really for any neuromusculoskeletal injury, needs to address not only the site of pain but the predisposing factors. Like we stated above there are potentially 5 underlying etiologies that “caused” the hamstring to become injured. Running fast is not the pathology; the pathology makes a normal activity like sprinting, abnormal. Keying in on all 5 of these potential problems with a progressive passive and active care approach will prepare the body for a return to normal activity.
Passive Care- A collection of manipulation, soft tissue mobilization, joint mobilization and modalities is utilized to facilitate the healing process and coerce the tissues to heal within the appropriate framework of the structure that is injured. Read more about tissue healing here. Scarring of an injury is a positive thing initially and that is why, depending on the injury severity, we allow 3-7 days of no treatment other then ice, a modality (Electrical stimulation, Ultrasound, Laser therapy, etc.), and light muscle work to the injury site. Any joint restrictions, or associated dysfunctions found on examination will be treated as appropriate. For the direct injury site however, we want to allow for initial scarring which provides a framework for healthy tissue to build on. After this acute phase (3-7 days) we progress into more aggressive tissue work, mobilizations, range of motion exercises, and start to introduce rudimentary rehabilitation of any neuromusculoskeletal dysfunctions found.
When doing any kind of rehabilitation it is important to remember that rehab is a relearning for the most part. Yes strengthening is a part of the process but the ultimate goal of rehab is to make sure the neuromuscular patterns of movement and proper muscle utilization is attained. I would say that ALL hamstring injuries are due to an issue with neuromuscular control and NO hamstring injuries are based on strength alone. A proper rehab progression addresses this; So no more isotonic “leg curls” seriously. Rehab exercises that address lumbopelvic control, eccentric strengthening and sport specific demands in output and movement pattern are essential.
Active Care- This component of care can begin on day 3-7 depending on the injury severity. Active care is defined as any and all of the rehabilitative exercises that are prescribed. As you will see in the video, rudimentary exercises are utilized first to correct movement patterns associated with lumbopelvic control, posterior chain utilization and isometric strength. This is also the sub-acute phase of care, as the tissues are healing it is desirable to have as minimal stress to the affected tissue. Once we have achieved pain free, bilaterally symmetrical range of motion, as well as bilateral symmetry in resistive strength, we can progress the patient or athlete into a rehab/performance training continuum. Injury severity will guide the speed in which performance training progresses. Initially the main goal of the dynamic power/speed drills or externally loaded movement patterns (deadlift, squat, etc.) neuromuscular training is the key. The volume and intensity of the exercises needs to match the ability to produce the desired movement or complete the drill with no biomechanical faults. Retraining and strengthening without reeducating the dysfunction will lead to recurrence of the injury. Ultimately this progression will lead to what will become performance training as opposed to rehab. It is however important to continue to reinforce good body mechanics through a good dynamic warm up before any sport specific training or practice. Nutritional considerations are a big part of returning to 100% or just increasing your performance or preventative ability. For more information and an in depth look regarding supplementation and nutritional support check out last month’s article here.
Hamstring Answers with The Thinker
The video below takes us through the implementation of diagnosis; passive care management and active care progression. The video features James Smith, Program Director at Juggernaut Training Systems and EliteFTS.com’ s “The Thinker.”