Why are hamstrings so difficult to rehabilitate? Sure...muscle imbalance, poor core stability, pelvic torsion, adverse neural tension can all be to blame. But perhaps we have not taken into enough consideration the way the muscle tissue was injured. Hamstring injuries are not homogeneous after all. In a brand-spanking new article Askling et al (2012) investigates the method of hamstring injury and the prognosis following injury.
Askling et al (2012) break down hamstring strain into two types: 1) Stretching injuries and 2) High speed running injuries.
Stretching injuries occur when the hamstring tendon is lengthened beyond its normal elastic/plastic tearing point. This usually occurs when the athlete's knee and foot are at their highest elevation at the end of the kick – the combination of hip flexion and knee extension. This movement puts the hamstring in a position of extreme stretch, most commonly injuring the semimembranosus tendon at the ischial tuberosity (Askling et al, 2006, 2007). Unfortunately the combination of poor rehabilitation protocols, premature return to the field and the fact the tendons located near the ischial tuberosity have a poor blood supply, lead to this particular injury having a poor prognosis.
This particular injury needs a prolonged rehabilitation period. Passive stretching should be avoided in the first week to avoid further pain and tearing at the proximal attachment. Players, trainers and coaches should be informed that although these injuries do not seem to be as severe as more distal intramuscular hamstring injuries, they take much longer to heal due to the time it takes for remodeling of the tendon to occur (Garrett el al, 1984).
Conversely, high speed running injuries to the hamstring are usually located at the muscle-tendon junction of the biceps femoris. Although these injuries usually result in greater initial pain, bleeding and functional loss, they do not require as long a rehabilitation time as the stretching type of injury. Silder et al (2008) believe the biceps aponeurosis scarring which occurs after the injury, may allow for alternative force transmission paths, and therefore a faster return to activity.
Intramuscular biceps femoris strains usually present with greater VAS pain scores, greater weakness, larger range of motion loss and more tenderness to palpation. A number of tests which measure range of motion, pain and strength can provide a good estimate of the time it may take to rehabilitate this type of hamstring injury (Schnieder-Kolsky et al, 2006).
Although these injuries heal faster than the stretching type of hamstring strain, they still need to be given the respect they deserve. High load exercises and passive stretching should be avoided with this type of injury in the initial stages of rehabilitation (Askling et al, 2012).
Again, players, trainers and coaches need to be made aware of the fact that although this injury may feel better in the initial stages of rehabilitation compared to the stretching type of strain, it is imperative that symptoms are not provoked, so as not to further prolong the rehabilitation time.
Prior to the past couple of years, I used the Sherry and Best (2004) hamstring rehabilitation protocol for my hamstring tears. I now use the below protocol by Heiderscheit et al (2010), which provides a very detailed 3-phase hamstring rehabilitation protocol. The authors note that individual attention needs to be placed on the sets/reps for each patient and adjusted where appropriate.
Any thoughts regarding this new and interesting article by (Askling et al, 2012) are welcomed.
- Protect scar development
- Minimize atrophy
Ice: 2-3 times/Therapeutic Exercise (performed daily):
- Stationary bike × 10 min
- Side step × 10 m, 3 × 1 min, low to moderate intensity, pain-free speed and stride
- Grapevine × 10 m, 3 × 1 min, low to moderate intensity, pain-free speed and stride
- Fast feet stepping in place, 2 × 1 min
- Prone body bridge, 5 × 10 s
- Side body bridge, 5 × 10 s
- Supine bent knee bridge, 10 × 5 s
- Single limb balance progressing from eyes open to closed, 4 × 20 s
- Normal walking stride without pain
- Very low speed jog without pain
- Pain-free isometric contraction against sub-maximal (50-70%) resistance during prone knee flexion (90°) manual strength test
- Regain pain-free hamstring strength, beginning in mid-range and progressing to a longer hamstring length
- Develop neuromuscular control of trunk and pelvis with progressive increase in movement speed
- Protection: Avoid end-range lengthening of hamstrings while hamstring weakness is present
- Ice: Post-exercise, 10-15 min Therapeutic Exercise (performed 5-7 d/wk):
- Stationary bike × 10 min
- Side shuffle × 10 m, 3 × 1 min, moderate to high intensity, pain-free speed and stride
- Grapevine jog × 10 m, 3 × l min, moderate to high intensity, pain-free speed and stride
- Boxer shuffle × 10 m, 2 × 1 min, low to moderate intensity, pain-free speed and stride
- Rotating body bridge, 5 s hold each side, 2 × 10 reps
- Supine bent knee bridge with walk outs, 3 × 10 reps (
- Single limb balance windmill touches without weight, 4 × 8 reps per arm each limb Lunge walk with trunk rotation, opposite hand-toe touch and T lift, 2 × 10 steps per limb
- Single limb balance with forward trunk lean and opposite hip extension, 5 × 10 s per limb
- Full strength (5/5) without pain during prone knee flexion (90°) manual strength test
- Pain-free forward and backward jog, moderate intensity
- Symptom-free (eg, pain and tightness) during all activities
- Normal concentric and eccentric hamstring strength through full range of motion and speeds.
- Improve neuromuscular control of trunk and pelvis
- Integrate postural control into sport-specific movements
Ice: Post-exercise, 10-15 min, as needed Therapeutic Exercise (performed 4-5 d/wk):
- Stationary bike × 10 min
- Side shuffle × 30 m, 3 × 1 min, moderate to high intensity, pain-free speed and stride
- Grapevine jog × 30 m, 3 × 1 min, moderate to high intensity, pain-free speed and stride
- Boxer shuffle × 10 m, 2 × 1 min, moderate to high intensity, pain-free speed and stride
- A and B skips, starting at low knee height and progressively increasing, pain-free
- A skip is a hop-step forward movement that alternates from leg to leg and couples with arm opposition (similar to running). During the hop, the opposite knee is lifted in a flexed position and then the knee and hip extend together to make the next step.
- B skip is a progression of the A skip, however the opposite knee extends prior to the hip extending re-creating the terminal swing phase of running. The leg is then pulled backward in a pawing type action. The other components remain the same as the A skip.
- Forward-backward accelerations, 3 × 1 min, start at 5 m, progress to 10 m then 20 m (
- Rotating body bridge with dumbbells, 5 s hold each side, 2 × 10 reps
- Supine single limb chair-bridge, 3 × 15 reps, slow to fast speed
- Single limb balance windmill touches with dumbbells, 4 × 8 reps per arm each leg
- Lunge walk with trunk rotation, opposite hand dumbbell toe touch and T-lift, 2 × 10 steps per limb
- Sport-specific drills that incorporate postural control and progressive speed
- Full strength without pain
- 4 consecutive repetitions of maximum effort manual strength test in each prone knee flexion position (90° and 15°)
- Less than 5% bilateral deficit in eccentric hamstrings (30°/s):concentric quadriceps (240°/s) ratio during isokinetic testing
- Bilateral symmetry in knee flexion angle of peak isokinetic concentric knee flexion torque at 60°/s
- Full range of motion with pain
- Replication of sport specific movements near maximal speed without pain (eg, incremental sprint test for running athletes)
Askling, C.M, Malliaropoulos, N & Karlsson, J (2012) High-speed running type or stretching-type of hamstring injuries makes a difference to treatment and prognosis, British Journal of Sports Medicine, vol 46(2), pp86-87
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Heiderscheit, B.C, Sherry, M.A, Silder, A, Chumanov, E.S & Thelen, D.G (2010) Hamstring strain injuries: recommendations for diagnosis, rehabilitation and injury prevention, Journal of Orthopaedic & Sports Physical Therapy, vol 40(2), pp67-81
Silder A, Heiderscheit BC, Thelen DG, Enright T, Tuite MJ. MR observations of long-term musculotendon remodeling following a hamstring strain injury. Skeletal Radiol. 2008;37:1101–1109.
Small, K, McNaughton, L, Greig, M & Lovell, R (2010) The effects of multidirectional soccer-specific fatigue on markers of hamstring injury risk, Journal of Science & Medicine in Sport, vol 35, pp120-125
Schneider-Kolsky ME, Hoving JL, Warren P, Connell DA. A comparison between clinical assessment and magnetic resonance imaging of acute hamstring injuries. Am J Sports Med. 2006;34:1008–1015
Sherry M, Best T. A comparison of 2 rehabilitation programs in the treatment of acute hamstring strains. Journal Of Orthopaedic & Sports Physical Therapy [serial online]. March 2004;34(3):116-125
Yeung, S.S, Suen, A.M.Y & Yeung, E.W (2009) A prospective cohort study of hamstring injuries in competitive sprinters: preseason muscle imbalance as a possible risk factor, British Journal of Sports Medicine, vol 43, pp589-594