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Why Aren't Hamstrings as Strong as Quads?

If the hamstrings are predominantly fast-twitch fibers in most people and the quads are predominantly slow-twitch fibers, then why aren’t the hamstrings at least as big and strong if not even bigger and stronger than the quads?

Line of pull. Cross sectional area

Physical priorities… in other words, the way we are designed makes the quads dominant in most movements. Thus, the hams get much less stress.

Some thoughts on top of the others from ID and JP

If they are largely fast twitch they dont need to be as physically big to produce the necessary strength

Most raw lifters can deadlift (hamstring emphasis) more than they can squat (quad emphasis) not a perfect example but shows you they are strong for their size.

Quads are slow twitch? Mine certainly aren’t :slight_smile:

I think most people do everything they can to shift stress onto their quads rather than their hamstrings due to mobility issues common to our society.

[quote]Gl;itch.e wrote:
Some thoughts on top of the others from ID and JP

Most raw lifters can deadlift (hamstring emphasis) more than they can squat (quad emphasis) not a perfect example but shows you they are strong for their size. [/quote]

To add a side note to this, the quads do aid a little in hip extension via the rectus femoris. I’m not sure how much of a difference it makes though, as I think it is pretty obvious that the hamstrings do, by far, most of the hip extension in this movement.

-Zep

quads may be ‘bigger’ but im not sure why you think stronger. Wide squats vs narrow, dls versus squats, front squats vs regular squats, each one with more weight emphasizes hams more than quads IMO

[quote]Gl;itch.e wrote:
Some thoughts on top of the others from ID and JP

If they are largely fast twitch they dont need to be as physically big to produce the necessary strength

Most raw lifters can deadlift (hamstring emphasis) more than they can squat (quad emphasis) not a perfect example but shows you they are strong for their size. [/quote]

I raw pull way more than I raw squat. My quads till lately appeared much larger than hamstrings, slowly fixing that.

[quote]Bull_Scientist wrote:
If the hamstrings are predominantly fast-twitch fibers [/quote]

…they are not. This is nonsense.

[quote] in most people and the quads are predominantly slow-twitch fibers [quote]

…same as above

as previous posters have said. More accurately,

hamstring=fusiform muscle. Fibers in line with tendon, more efficient transfer of force to movement across a wider range of contraction velocities.

quadriceps=pennated muscle group. Fibers aligned at angle to line of pull (tendon), therefore anatomically capable of ‘packing more fibers in’. Greater maximal force output at slow contraction velocities, greater drop off in force output as contraction velocity increases (as compared to hamstrings) owing to increased viscoelastic resistance to crossbridge binding.

Force output of quads will nearly always be greater than hamstrings across contraction velocity speeds. Observed balance in clients/patients tends to occur at knee joint contraction velocities approx 250-300 degs/sec (sporting applications rather than weightlifting).

I would also consider the movement being performed, or function of the muscle. Consider, if you would, that the bicep performs a similar function for the upper arm that the hamstrings do for the leg, and the quads perform similar function to the triceps. There are more muscles (3 vs 2) and are often larger in the arm for extending as opposed to contracting, similar to the leg.

Size-wise is open for debate. Depending on an athlete’s focus and workout, size will vary. That’s similar to folks who have great abs but no lower back, great chest, no upper back, etc. etc. Muscular imbalances occur everywhere. Assuming no muscular imbalance and each opposed group is worked equally, then the muscles are the size required to perform the current function or in response to the applied stimulus.

Hope that made sense.

Form follows function…

With this in mind you must consider lines of pull, ROM around a joint, muscle fibre orientation, dominant muscle fibre type, sites of attachment (origin & insertion), nerve innervations, motor programming, activities of daily living and of course exercise selection.

All these will affect how a muscle functions and in turn its form. Comparing the strength of the hams against the quads is like comparing apples and oranges - two separate muscle groups with different functions with the only commonality being they are located on the upper leg.

[quote]Iron Dwarf wrote:
Physical priorities… in other words, the way we are designed makes the quads dominant in most movements. Thus, the hams get much less stress.
[/quote]

We are designed to be balanced with agonist and antagonist pairings working in tune with one another. That is not to say there is a 50/50 distribution of work across a joint but the work allocated to a specific muscle is dictated by the shape and arrangement of the muscle / muscles / tendons, origin and insertion points on the bone, ROM around a joint, which in itself has structural features that will further dictate function and work distribution. One muscle is not designed to be dominant over another muscle when working around a joint to produce smooth pain free movement. It is only when faulty movement patterns persist that these instances arise and become problematic.

The reason why people may be quad dominant is down to activities of daily living e.g. sitting on your arse all day, over time weakens and inhibits the glutes and hams, tightens the Rec Fem, Psoas Major & Iliacus resulting in anterior pelvic tilt etc etc… Ask any regular person to contract their quads and they will more than likely be able to do so however ask them to contract their hams and you’ll probably get nothing as the mind muscle connection is non existent due to among other things inhibition etc…

Deads are hip dominant, not ham dominant. Look at the cross sectional area of your ass as opposed to your vastus or quads.

How do you know if a muscle has fast twich or low twich fibers?It depends on genetics,race etc so why are you overthinking it?

The physical culture tends to romanticize the hamstrings. They are important muscles but not more so than anything else.

[quote]jp_dubya wrote:
Deads are hip dominant, not ham dominant. Look at the cross sectional area of your ass as opposed to your vastus or quads. [/quote]
This is true. Which is why I used emphasis, and not dominant, to describe their utilisation in those exercises. You could say that Deads & Squats are both hip dominant movements. They’ve certainly given me some junk in my trunk. Deads Ive always felt more in hams and lower back, Squats glutes and quads. And most people seem to report the same. Hence the emphasis I mentioned. Not a lot of people would just do squats if building hams was their intent (though Im doing well with box squats for this)

[quote]Zeppelin0731 wrote:

[quote]Gl;itch.e wrote:
Some thoughts on top of the others from ID and JP

Most raw lifters can deadlift (hamstring emphasis) more than they can squat (quad emphasis) not a perfect example but shows you they are strong for their size. [/quote]

To add a side note to this, the quads do aid a little in hip extension via the rectus femoris. I’m not sure how much of a difference it makes though, as I think it is pretty obvious that the hamstrings do, by far, most of the hip extension in this movement.

-Zep[/quote]

No, the Rectus Femoris does not aid in hip extension, it is a hip flexor and knee extensor.

Agreed with others regarding hamstring strength vs quad strength