Hmmm …. I know I’m going to respectfully stir things up with this post – but hopefully we can debate and learn! 🙂
[I’ve spent a little time trying to understand hamstring injuries becuase I had 2 very early on in my playing career – once I realised the first rehab program was incorrect to emphasise flexibility – I focused on strength training I never got as much as a strain after that for the rest of my 10 years or so playing.]
I actually disagree with the emphasis on Nordic Curls.
While I agree they are useful as a hamstring exercise I actually think they are overrated.
As we know most of the hamstring action occurs around the hip – even during the so-called ‘eccentric phase’ as the athlete slows to change direction – the focus and action is actually around hip and knee stabilisation (to prevent an anterior femoral slide and protect the ACL) – but it’s primarily anterior knee stabilisation.
The reason some hamstrings tend to fail at is called the ‘eccentric phase’ is actually at the point where the hamstring is switching on again to extend and propell the athlete – it is NOT in knee flexion which a Nordic Curl empahsises. It is a neural issue (similar to reciprical inhibition) caused by fatigue and residual tension – most often in the quads.
It is still, though, a hamstring action that occurs around the hip.
My understanding of the biomechanical action is thus ….as the athlete slows they bend at both knee and hip – the hips and femur must be held stable by the hamstring group. Between VMO and Glute, knee rotation is prevented and the hamstrings prevent the femur sliding over and snapping the ACL – meanwhile the Quads are also working to stabilise the knee – then at a split second the hamstring must swtich from stabilisation to contraction to extend the HIP and propel the athlete again – it is this ‘switch’ from passive/stabilisation action to contraction that is the problem. If the quads are not able to work in unison and relax fast enough the hamstrings pull themselve’s self apart.
Any residual fatigue or nerual impingement will cause timing of relaxation and activation of the hamstrings and quads to compete against each other.
I have rehabbed players with hamstring problems never having done any Nordic Curls, Glute Ham work or minimal Hamstring knee flexion work. While I refer to those of you more experienced and better quailfied I have yet to see or justify the reasoning of strengthing knee flexion.
I focus on Good mornings, Romanian Deadlifts with slight knee bends and even with slightly greater than normal knee bends once the back arch is held. I occasionally will do 10 reps of light knee flexion hamstring curl just to maintain some strength and flush the muscle at the end of a session. Sometimes I use a theraband to do this trying to get the athlete to relax the hamstring and switch it on again just as the knee extends to 180 and teach it to fire again fast.
I believe that hamstring strength is critical and the most important factor in hamstring injury prevention – far more so than flexibility.
Also very important is adductor strength as EMG studies have shown very high activation of the adductors in sprinting and we can imagine the increase if we translate this to rugby with change of direction or even slight movements.
So wider or ‘not-to-narrow’ deadlifts, lunges and squats are critical here in my humble opinion.
As a rough guide … for rehab I work on hamstrings on a 2 or 3 day rotation – Strength & Endurance.
Day 1 – Strength, low reps, hip extension focus, Good mornings, RDL’s etc very slow eccentric
Day 2 – Endurance, High rep, low weight theraband-type work, hip extension, fast contraction & fast (but controlled) eccentric – teaching relaxation.
The reason for the very slow eccentric is, unlike some, not because I believe the hamstring goes during an eccentric action when it gets injured – but
(1) rather because there is far greater neural activation, rate coding and also
(2) becuase the greater the linear tension the far greater the chance of fibre realingment deep in the muscle belly – FAR more than any cross friction can achieve no matter what a physio might suggest.
I cannot see how fibres so small to the naked eye, deep in a muscle belly can be effected by X-friction no matter how strong the therapist.
Anyway … I think I attempted to kill enough sacred cows there for one post – but I’ll be interested in your thoughts and I hope you at least understand my (perhaps flawed) rationale!