Muscle Anatomy

If you have any questions just ask about terminology o.k.

AUG 2 2006
GROUP 1 = Quadriceps

MUSCLE Of the Day


Rectus Femoris
– one of the four quadriceps muscles, it is located on the anterior femur and is the longest and most anterior of the quads. It is a compound muscle – crossing both the hip and knee.

(Where the muscle originates)
Origins = Anterior Head - AIIS (anterior inferior iliac spine) Posterior Head – upper margin of acetabulum

(Where the muscle Inserts)
Insertion = via Patella & its ligament to tibial tuberosity

Actions = Compound Muscle: Extends leg at the knee
Flexes thigh at hip

Synergists = These muscles assist Rectus Femoris
In Leg Extension: Vastus Group
In Hip Flexion: Iliopsoas, Sartorius, semitendinosis

Antagonists = These muscles work against Rectus Femoris
In Leg Flexors:
Hamstrings, Gastrocnemius
In Hip Extenders:

Nerve Supply = Femoral Nerve: L2-L4

Associated Trigger Points = At superior musculotendonous junction - and can refer pain to the entire anterior thigh, but most especially near the knee

Stretching = Standing Quad Stretch w/ hip extension emphasis

Strengthening = Squats and Leg Press

Group 1 continued :

11C = Vastus Lateralis

Vastus Lateralis

Origin:
1. greater trochanter
2. lateral lip of linea aspera
3. lateral intermuscular septum
Insertion:
1. common quadriceps tendon into patella
2. tibial tuberosity via patellar ligament
Action:
1. extends knee
2. can abnormally displace patella
Blood: lateral femoral circumflex artery
Nerve: branches of femoral nerve, [L2],3,4
Stretching = Standing Quad Stretch w/ hip extension emphasis
Strengthening = Squats and Leg Press


Extra information I found :
It is often desirable to obtain muscle samples for direct analyses in order to study the effects of diet, exercise, disuse, or disease on human skeletal muscle. The vastus lateralis muscle has been the muscle of choice for biopsies because of its mixed fiber type composition, trainability, and accessibility.
A study was also conducted and found most of the vastus lateralis muscle samples (132 of the 150) had between 25–60% Type I fibers. The percentage area of Type I was significantly smaller, and the percentage area of Type IIA significantly larger for the men compared to the women. Although many studies have found gender differences related to fiber size, conflicting reports have been published regarding the overall proportion of fast and slow fibers in the vastus lateralis muscle of men vs women.

AUGUST 4 2006
Group 1 Continued:
Vastus Medialis 11B


The vastus medialis is the muscle that brings the kneecap inward, holding it in the position it should be. This can relieve stress on the knee, as well as treat runner's knee. It has a bulging teardrop appearance located on the inner front corner of the lower thigh, and can be divided into two portions the vastus medialis longus, which extends the knee, and the vastus medialis oblique. The vastus medialis is the muscle that extends the leg the last 10% and is therefore very important while walking.

Origin = Starts at the lower 1/2 of the intertrochanteric lines, medial lip of linea aspera, upper part of medial supracondylar line, medial intermuscular septum tendons of adductor magnus and the adductor longus.

Insertion = Medial border of the patella by the ligamentum patella into the tibial tuberosity.

Innervation = Femoral Nerve

Action = Leg extension, and draws knee medially

Referred Pain = inside of anterior knee and up to about mid thigh

Strengthening = Lunges

Stretching = Quadriceps Stretch
Lie face down on a mat.
Lift your right leg up towards your buttocks.
Reach around with your right hand and grasp your foot. -Slowly pull downwards, stretching your quadriceps to the furthest comfortable position.
Hold this position for at least 15-30 seconds.

Medialis Weakness:
Increased risk of knee injury (chondramalicia) during knee extension activities. The patella becomes laterally displaced with the pull of the vastus lateralis. This patella tracking problem can produce wear on the inferior petellar surface. Greater pain is usually experienced during leg extension activities in which the knee is a greater than a 20 to 30 degree angle.

Examples of affected exercises:
Leg Press , Squat , Leg Extension

Example preventative / corrective exercises:
Single Leg Extensions (last 20 degrees of extension) , Leg Press (last 20 degrees of extension)

OMG you are soooo good! Can you help me with right knee inserts...? what are the excercises that will help strenghten?

Group 1 Continued
Vastus Intermedius



The vastus intermedius is and extensive muscle that lies deep to all the other quadriceps bellies, adding muscular fullness under them. Its fibers end in a superficial aponeurosis, which forms the deep part of the Quadriceps femoris tendon.

Origin= proximal 2/3 of the anterior and lateral lateral surfaces of the femur, lower 1/2 of the linea aspera, upper part of the lateral supracondylar line; lateral intermuscular septum

Insertion= by tendons of the rectus and vastus muscles into the superior border of the patella
(*Another sources says lateral side of patella) and by the ligamentum patella into the tibial tuberosity

Action = extends the leg at the knee

Nerve supply = Femoral L2, L3, L4

Synergists = rectus femoris, vastus medialis, vastus lateralis

Arterial supply = descending branch of LFCA

Antagonists = Hamstring group

Strengthening = Lunges

Stretching = Quadriceps Stretch

maybe if i shave my skin off my quad i can have those same lines and cuts lol

good stuff tre

Hi Trel, this is a great review, I'm a LMT also! I've been out of school for 3 years and mainly do it part-time. It's such a physical job, but I luv it.

I really slacked off this summer(doing massages) while I was training for Figure comp.s but I'm back to work as soon as the kiddies get back to school.

Great thread!!

treilin said:

AUGUST 4 2006
Group 1 Continued:
Vastus Medialis 11B

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Click to expand...

What is 18B? That's the part behind my knee that gets strained and makes my knee lock up.

Biceps femoris (short head) Don't you agree Trel?

Just so you all know.. I am answering questions through karma so this thread doesn't get so cluttered. So don't think I am ignoring people!!

Mrs Jnuts You are right, but also the long head both connect on the Fibular head.