7/2/06

Hamstring Injury Prevention Exercise Selection

The following is an excerpt from an article that Dean Benton and I wrote for Sport Coach in Australia.

Continuum of injury prevention/performance enhancement exercise:
The placement of exercises on the continuum is ultimately determined by the relationship to the function of the hamstring in actual running. It helps to look at the continuum as progressing from a low speed, high force emphasis, to high speed/high force exercises that are ballistic in nature. At the general end of the continuum the exercises do not as closely resemble the criteria activity. As the exercises progress along the continuum the movement pattern is similar and force time characteristics more closely resemble the actual activity. The goal of all of these is multifaceted, to improve functional strength, improve intermuscular coordination and improve mechanics of sprinting.

General

Special

Specific

Low step ups

High Step-up

Lunge & reach – 3 planes

Walking lunge & high knee

Hanging horizontal bridge

Cable hip extension

Resisted moonwalks

Straight leg bounds

B drills

15 Degree Hill Sprints

Complementary exercises:

The following training modules contain complementary exercises that should be implicit in a comprehensive strength & conditioning program. Although they may not specifically train the ”hamstrings” they involve the hamstrings in patterns of movement that force them to work through amplitudes of movement and at speeds that that prepare the hamstrings for the stresses they will encounter in sprinting and multi directional movement.

Running technique training – This should be fairly obvious, but the attention to detail necessary the time necessary puts coaches off. This does not entail making the athlete conscious of hamstring firing or involvement, rather the emphasis is on the rhythm and flow of the movement. Posture and relaxation are primary considerations. This should involve work on top speed running starting at ten meters and working up to alternating periods of hitting top speed and floating at top speed. It is also imperative to work on mechanics of running involving curves and angles to condition the body for the differing demands that put the hamstrings at risk. Stair running is a good means to reinforce proper top speed mechanics without undo stress on the hamstrings. The stair sprints should not exceed ten seconds in duration. The emphasis is on hips over the foot at contact and tall posture.

Mach sprint drills – The primary emphasis of these drills are to superficially strengthen the muscle used in sprinting. There is some carryover to technique but they are primarily specific strengthening exercises. The “B” series of foreleg extension and pawing back has little relationship to technique, but it is a primary exercise to strengthen the hamstrings as they work to decelerate the foreleg. The skipping aspect of the drills serves to train the stiffness component so important to learn to optimize ground contact. When executing the skips it is imperative to actively drive the foot into the ground to set up the proper ground reaction.

Low amplitude hops/jumps – This serves to facilitate muscle stiffness. Stiffness is the opposite of sagging which would be the leg collapsing at ground contact. This aspect has not received as much emphasis as its role in sprinting demands. Straight leg bounds, ankle bounces, low hurdle hops all reinforce stiffness. The emphasis here should be on the knee being almost locked. Emphasize bouncing type movements which result in very short ground contact times. Cue the athlete that the ground is hot.

Hurdle dynamic hip mobility exercises – It is hip mobility or a lack thereof that is the genesis of many hamstring problems. These drills should be incorporated daily as part of warm-up or cooldown. Without proper hip mobility the leg will not be able to work through the full range of motion. This limitation will eventually lead to flawed mechanics especially in a fatigued state.

Resisted hip abduction/adduction exercise – The hip abductors and adductors play a major role in stabilization. In fact the Adductor Magnus is sometimes referred to as the fourth hamstring. If they are weak or not coordinated with the hamstrings more strain will be placed on the hamstrings.

15 deg hill sprinting – Hill sprinting at a 15 degree grade provides an excellent means to develop good top speed mechanics. It is virtually impossible to overstride sprinting up hill.

2 Comments:

At 7/2/06, 12:43 PM, Blogger welch said...

Vern,
This is tremendous stuff. By chance have you put together a similar list for calf strengthening?

 
At 7/2/06, 4:46 PM, Blogger Joe Przytula said...

I noticed you placed "resisted hip adduction/abducion exercise" on the list. I noticed in the Bosch & Klump book, they recommend this also, by way of something that looks like a 4 way hip machine. While I agree with the adductors role in preventing hamstring injuries, I disagree with the method because it is inconsistent with the adductors funcion. Sure, they can adduct the leg, but not in gait. EMG studies show the adductor magnus plays a major role in decelerating hip flexion and accelerating hip extension. The opposite would be true for the longus.

Bosch & Klump go on to say monoarticular muscles like the short head of the bicep femoris & adductors are "dumb" and should be trained in isolation. They also recommend an exercise that looks something like a glut/ham raise.

Every muscle has a triplanar function. I'm not ready to go out and buy a 4 way hip machine or roman chairs or glut/ham machines yet. While I definately think those guys are on to something, they could use some of your input when you go over there in the fall.

 

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