Hammies more efficient than quads at speed

[kitkat1]

THIS PARAGRAPH COMES FROM AN EBOOK DISCUSSING DEVELOPMENT OF VERTICAL JUMP FOR BASKETBALL. ANYONE CARE TO OFFER EXPERT COMMENT ON THE HIGHLIGHTED STATEMENT PLEASE.

Muscular Contributions To Each Style
It’s also worth mentioning that the muscular contributions to a uni-lateral (single leg)
takeoff vs a bi-lateral (2 legged) take off are different. Both of them rely on the muscles
of the glutes, hamstrings, quadriceps, and calves, yet the contribution that each muscle
group provides changes depending on the style of jump. The unilateral jump relies much
more on the glutes, hamstrings, and calves with the quadriceps providing a lesser role.
The bilateral jump relies on the quadriceps musculature for up to 50% or more of the
power output. The glutes and hamstrings are inherently fast twitch muscles and tend to
be more efficient then the quadriceps when contracting at very high speeds such as those
that occur in a unilateral take off. The quadriceps tend to be more efficient when
contracting a little slower.

[hornblower]

how can we use this information in our training? would one-legged squats hit the hamstrings more than the quads and be more beneficial to sprinting??

[no23]

I'd like to see the EMG data or whatever that suggests this.

[martn76]

how can we use this information in our training? would one-legged squats hit the hamstrings more than the quads and be more beneficial to sprinting??

No, but one leg hops for speed would probably do it and ham strength work with an accentuation towards fast concentric actions with a pause between reps would also do it. Heavy eccentric weights eg lowering a heavy weight but fast concentric would also do it. Avoiding fatigue in sets of ham work IF you are aiming to develop efficiency would also do it. If you are looking for speed-strength as opposed to strength/strength endurance then intra rep pauses between reps would also help so doing an explosive ham curl with (hip involvement) then resting for approx six seconds then another rep and so on will improve efficiency of hams.

[duxx]

Form dictates function....
Bosch and Klomp (2005) wrote that hams, calfs are more pennate muscles bi-articular more suited for reactive work and energy trnasfers (isometrical), while glutes and quads are more parallel and uniarticular suited for concentric explosive actions.
The more the 'elastic' jump, the more the contribution from hams and calfs.... the deeper the jump and slower, the greater the contribution of quads and glutes.

Kelly Bagget wrote whole book (Vertical Jump Bible) describing these two styles of jump(ers): elastic and strong, evaluating athletes and planning training according the their pro's and con's. Recommended reading, alomng with Bosch and Klomp - Running Biomechanics and Physiology in practice.

[kitkat1]

Form dictates function....
Bosch and Klomp (2005) wrote that hams, calfs are more pennate muscles bi-articular more suited for reactive work and energy trnasfers (isometrical), while glutes and quads are more parallel and uniarticular suited for concentric explosive actions. The more the 'elastic' jump, the more the contribution from hams and calfs.... the deeper the jump and slower, the greater the contribution of quads and glutes.

Kelly Bagget wrote whole book (Vertical Jump Bible) describing these two styles of jump(ers): elastic and strong, evaluating athletes and planning training according the their pro's and con's. Recommended reading, alomng with Bosch and Klomp - Running Biomechanics and Physiology in practice.

DUXX!!! I was hoping you would jump in here. But let me be the dummy and ask you to "please explain" in more basic (or more commonly understood) terms what you have so concisely stated in the bold copy ... coz I'm not sure I understand what you just wrote here

Isn't it : "Form Follows Function"

yes, the original text is from Kelly's mostly excellent ebook. A lot of his advice could have come directly from a track and field coaching manual.

[Charlie Francis]

The glutes and hamstrings are inherently fast twitch muscles and tend to
be more efficient then the quadriceps when contracting at very high speeds

i think this is fairly well understood, both because of the FT composition and the directionality of the fibre, particularly in the hams.

[duxx]

DUXX!!! I was hoping you would jump in here. But let me be the dummy and ask you to "please explain" in more basic (or more commonly understood) terms what you have so concisely stated in the bold copy ... coz I'm not sure I understand what you just wrote here

Isn't it : "Form Follows Function"

yes, the original text is from Kelly's mostly excellent ebook. A lot of his advice could have come directly from a track and field coaching manual.

Kitkat,
It is hard to explain the terms in a short post! My advice to you is to get the book (Bosch and Klomp)-it is one of the brightest books I have ever read. It explains it all
The whole story is that every mucle is built to have specific role in human motion. Altought muscles can function in various ways (hams are build to function reactively, but you can do the ham curls), the greater the speed of execution, the more muscle work according to their specialized structure. Bosch and Klomp explained this with their 'Centrifuge model' (p.349).
They suggested generalized classification of the muscles:
Concentric-explosive muscles
- Monoarticular (cross one joint)
- Paralle fibered
- Positive work/power training
- Greater ROM of force production (flatter the F-L relation)
- gluteus maximus, iliopsoas, vastus segments of quadriceps.
- 'Dumb' muscles

Reactive-elastic muscles
- Bi-articular (cross more than one joint, 2)
- pennate structure
- important passive structures (tendons, fascia...)
- Working reactivelly (SSC - stretch shortening cycle)
- Able to asorb and process external force
- Suited for 'isometrical work' (narrow F-L relation) - Isometry and pre-contractions are pre-requisites for 'elasticity', making the CE elemnt stiff and enabling the muscle to utilize SE (serial elements - tendons and 'stuff')
- erector spinae, hamstrings, triceps surae, rectus femoris, abdominal muscles
- 'Inteligent muscles' - need more effort and coordination to be used effectivelly

'Naturally this is arough division. In reality, muscles are flexible and can have properties of both groups. However, this diviosion into two groups is usefull in practice, particulary when organizing training program' (B&K, p.350).

I think I get the following 'wisdom' form Novachek review paper. Since the kinetical and potential energyes are in phase, compared to walking (inverted pendulum), in running to insure movement eficeincy, human body must rely on two other mechanisms:
* Elasticity
* Energy transfers between joints

According to B&K, our understanding of muscles is/was being dominated by our model that muscles only overcome resistance... but this is only part of the story. Actually, the function of the muscle is more comphenesive:

- Overcomming resistance (force/power generation)
- Pre-stretching elastic tissues
- Energy transfer
- Facilitiation of other muscles by stressing them eccentrically

To explain you energy transfer of bi-articual muscles in short, take for this for example. The quads extend the knee, but since hams spans both the hip and knee, if the hams maintain their length (isometrics) like a stiff rope, they will 'transfer' force and thus energy from knee extension to hip extension. Or in other word, knee extension will produce hip extension. This 'energy transfer' hapens with all bi-acricualr muscles.

Facilitiation of other muscles by stressing them eccentrically is another interesting stuff.
During the push-of phase in acceleration phase of sprinting, the most power is generated by glutes and quads. Since gluteus maximus produces both hip extension and external rotation of the hip, torsion of the trunk and usage of the arm swing will produce the internal rotation of the hip of the stance leg and thus 'elongate' the gluteus maximus and this will in turn, according to F-V law reduce the contraction speed of the gluteus maximus which will in turn enable it to produce more force into the ground.

One another 'amaizing phenomena' is the muscle distribution in the body. During running, about 80% of energy is utilized to accelerate/deccelerate body segments. To improve body efficiency, the ammount of mass in distal segment should be reduced (this will reduce 'moment of inertia'). This is why calf muscles are bi-articual (gastrocs) and pennate which allow the to create greater isometrical force for the same muscle mass compared to parallel fibered muscles. To enable energy transfer from hip and knee extension toward foot extension (tripple extension), calfs function reactivelly/isometrically and transef force from more powerful muscles around knee and hip. This mechanism at the same time reduces moment of inertial (distal muscle mass) and increase power of ankle extension. Amazing!

This is all from this amazing book.

I guess you could digest this short post

[kitkat1]

Got it. Thanks Duxx

[kitkat1]

SERIOUSLY though, that's one of the most interesting and revelatory posts I've read. Thanks for putting so much effort into your reply. Duxx indeed.