How many heads of a muscle....

[suncloud]

So we know that biceps have two heads (long and short), the triceps have three, delts 3, chest 5. in doing shrugs, we find there's at least two, because shrugs and behind-the-back shrugs hit different parts of the traps...

this begs the question, how many heads of a muscle are in your back? there's at least 4 different muscle groups - do each of them only have one head?

so for those of you that know, post the head of different muscle groups, and how to target them.

i'll start

chest :
upper - incline bench / DB incline
middle - bench / DB bench
lower - dips / decline bench
inner - butterfly machine / pec deck
outer - DB flyes

serrattus :
one head? - straight arm pullovers

tricep:
lateral - reverse grip tricep pushdowns
medial - close grip bench
long - dips

delts :
anterior - front delt raises/military press
lateral - side delt raises/upright rows (wide grip)
posterior - face pulls/rear delt raises

biceps:
long head - concentration curls / narrow grip barbell curls
short head - DB curls / preacher curls / wide grip barbell curls




what about...
quads - i know there's 4 heads, how do you target each of them?
calves and the opposing calf muscle
brachialis
traps - two heads i assume?
lats
hamstrings - only one head?
rhomboids major and minor (infra-spinatus)
spinal erectors - erector spinae
teres major
abs
obliques
are there more?

reps for muscle heads and exercises that target them. lets put together a list that everyone can use. hopefully we'll all learn something new.

 

[stullsy]

whats do you mean your chest has 5 heads. the pectoral muscle only has upper and lower

 

[SRS2000]

Unless the muscle has multiple attachments or has fibers that run in different directions, it's very difficult to "isolate" just one area of that muscle. For example, the quads are a group of 4 muscles that all have a common insertion via the patellar tendon. Thus they all participate in knee extension. The three vastus muscle all originate somewhere on the femur. It is very tough to isolate any of these muscles from the other to any significant degree. Changing your stance in squats involves changing the angle of the femur at the hip joint and thus doesn't affect vastus recruitment much since they don't cross the hip joint. The rectus femoris is the only one that crosses the hip joint, so it is also involved in hip flexion.
Same principle with the different heads of the gastroc. Toes in or toes out calf raises are primarily due to rotating the whole leg at the hip and only has minimal impact on recruitment.
Study the anatomy and action of the different muscles and you can likely come to reasonable conclusions about whether specific areas of the muscle can be isolated or not.

 

[Rodja]

The "hamstrings" are 3 muscles: biceps femoris, semitendinosus, and semimembranosus. The is only one attachment for the pec major and one for the pec minor. However, the pecs also work in 3 separate planes of motion, which is the reason most train it from multiple angles. Traps are another example of this: they work in scapular adduction and also scapular flexion.

 

[ShakesAllDay]

how many heads of a muscle are in your back?

A bit scientific...

http://anatomy.uams.edu/anatomyhtml/muscles.html

 

[Flaw]

"heads" really only apply to bicep,tricep and shoulders. The quads consist of 4 different muscles.. not heads. The only heads you can really isolate are the heads of the shoulders. While doing elbow flexion for bicep exercises you work both heads and while doing extension of the elbow you are working all areas of the tricep. Sure you can feel it differently at certain angles but your still working the whole muscle. There's evidence of decline chest press activating the most muscle fibers of any chest exercise but your still working the whole chest. Even the upper pec minor. Incline chest press is like a military press at a slightly different angle. You hit shoulders more and pecs less.

As far as the calf goes there are 2 muscles there.