FUNCTIONS OF MAJOR MUSCLE GROUPS
1. Muscle: Rectus Femoris (Quads)
Function:
Hip flexion (with illiapsoas) and knee extension (with vastus
group--vastus lateralis, intermedius and medialis)
Exercises:
Cycling, leg press machine, vertical jumping, stair climbing, jump roping,
resisted knee extensions (these are usually incorrectly called the 'leg
extensions' on the machines. They should be called 'knee extension'.)
2. Muscle: Gluteus Maximus (Butt)
Function:
Hip extension and external rotation
Exercises:
Squats, cycling, jumping rope, stair climbing
3. Muscle: Gluteus Medius & Minimus & Tensor fasciae latae (Outer thigh)
Function:
Hip Abduction
Exercises:
Side-lying leg raises
4. Muscle: Adductor Magnus and Adductor Brevis & Longus (Inner thigh)
Function:
Adduction and external rotation and adduction, flexion & internal
rotation, respectively
Exercises:
Side-lying botton leg raises, manual resistance adduction exercises,
resisted adduction
5. Muscle: Gastrocnemius (Calf)
Function:
Plantar flexion at ankle (as in pointing the toes)
Exercises:
Hill running, jump rope, calf raises (with free weights), stair climbing
6. Muscle: Rectus Abdominus (the Abs)
Function:
Forward spinal flexion (though the focus here is 'joint action', it is
important to remember that the abs are responsible for torso
stabilization and good posture)
Exercises:
the old tried and true Crunches (with or without weights; go to the ABS
page for more info), bent-knee sit ups, though it is important to know
that when doing sit-ups, the hip flexors take over as you progress
beyond a 45 degree angle, so I personally believe that you get better
isolation of the abdominals with just crunches.
7. Muscle: External & Internal Obliques (front sides of the torso)
Function:
torso rotation
Exercises:
Twisting crunches (leading with the shoulder towards the opposite knee)
8. Muscle: Erector Spinae (back)
Function:
Trunk extension
Exercises:
Prone (face down) back extension exercises, dead lifts (NOT
recommended if you have a pre-existing back condition, or without the
supervision of a certified trainer)
9. Muscle: Pectoralis Major
Function:
Flexion, adduction, internal rotation
Exercises:
Push-ups, pull-ups, incline & regular bench press, climbing rope,
throwing
10. Muscle: Deltoid (shoulder)
Function:
Abduction (entire muscle), Flexion, internal rotation (anterior fibers),
Extension, external rotation (posterior fibers)
Exercises:
Lateral 'butterfly' exercises with free weights, over-head or 'military'
press with free weights
11. Muscle: Latissimus Dorsi
Function:
Extension, adduction, internal rotation
Exercises:
Chin-ups, rope climbing, rowing, any exercise that invollves pulling the
arms downward against a resistive force as in 'lat' pulls on the machine
12. Muscle: Trapezius
Function:
Elevation of scapula (upper), Adduction of scapula (middle), Depression
of scapula (lower)
Exercises:
Upright rows, shoulder shrugs with resistance
13. Muscle: Rhomboid Major (back; upper region)
Function:
Adduction & Elevation of scapula
Exercises:
Chin-ups, supported free weight bent-over rows (Make sure that you are
not bending at the hip only; your knees should be bent and your "butt"
out to distribute your weight more evenly, otherwise, you are putting
unnecessary stress on to your lower back!)
14. Muscle: Biceps Brachii (upper arm, above the elbow)
Function:
Elbow flexion
Exercises:
"Curling" with free weights, chin ups (Use full range of motion when
curling. Keep your "tailbone" to the floor and make sure the only thing
that moves are the elbows flexing and extending! Never use your back
for momentum. It's obviously not good for the back, but it also won't do
your biceps any good if another part of the body is doing the work for
them!)
15. Muscles: Triceps Brachii (opposite the biceps)
Function:
Extension at the elbow
Exercises:
Dips on parallel bars, push-ups (you can easily do dips on a Reebok
step by placing your hands each side the hips; keep your fingers curled
over the edge; if this bothers your wrists, place hand held weights each
side the hips on the bench and hold on to the weights while doing the
dips. You can also place some weights on to your lap to make it a little
harder. Try to use three or four risers on each side of the bench for
these.)