Bulletin 14 - June 2010
The Punt Kick – More on the Hamstring Saga

At the expense of sounding like the proverbial ‘broken record’ we note in this weeks press the same tired old stories dealing with hamstring injuries. If ever there was an issue demanding full attention from coaches it is the preparation of perhaps the most vulnerable muscle group, the hamstrings.

Coaches at all levels fail to recognize and understand the synergy between the two large muscle masses of the thigh, namely the quadriceps which lie at the front and the hamstrings that occupy the posterior compartment of the thigh. Both groups are heavily involved in any propulsive movement such as the drive from the right leg demonstrated by Sam Day in the photograph at left as he drives forward to intercept his opponent. The quadriceps, of course, are responsible for the explosive right knee extension but it is the hamstring group that the quadriceps rely on to produce the simultaneous hip extension. One does not, indeed cannot, occur without the other.

While the hamstrings must obviously shorten to achieve this action at the hip, they are at the same time being explosively lengthened at the knee as the more powerful quadriceps exert their full power there. Four muscles (quadriceps) at the knee versus only three (hamstrings) at the hip. David versus Goliath you might say. But this mismatch gets worse. Three of the four quadriceps are given the term ‘vastus’ meaning vast. This massive knee extensor group is pitted against the hamstrings, two of which are termed ‘semi’ semitendinosus and semimembranosus. In other words they are only half muscles. Poor old ‘David’ really cops a belting in this movement!

But it gets worse! The poor old ‘hammies’ in our game are called upon to perform a second and totally different action: that being the arresting of the kicking leg at the end of its swing phase. We refer to it in our book ‘The Science of Kicking’ as approximating the stopping of a ‘runaway train’ (Ch 10, p 58). It is precisely what we see in the photograph at right. Taken an instant after impact we note the knee of the kicking leg has been snapped into hyperextension, with the strain taken by the cruciate ligaments. To ease this load we see, too, the hamstrings ‘switched on’ to bring the knee back into flexion. Note the extreme tension in the lateral hamstring, biceps femoris, as it extends from the pelvis above the hip joint, all the way to the top of the fibula bone (arrow). This ‘elastic band’ needs not only to be very strong, but also very resilient. In other words it must have plenty of ‘give’ or as anatomists say, it must have a long habit length.

These two vital attributes, great strength and significant stretching ability can only be achieved with long hours of preparation in the gym beginning in the junior ranks, and under the watchful eye of attentive and well prepared coaches. Neglect the ‘hammies’ at your peril!

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