All muscles of the anterior compartment

of the medial compartment of the thigh. They are described later. In the upper lateral corner of the front of the thigh. we see the tensor fasciae latae. This is a muscle of the gjuteal region and is described in Chapter 5.

The sartorius is long, narrow and ribbon-like.

 It runs downwards and medially across the front of the thigh. It is the longest muscle in the body. Its attachments are given in  Its nerve supply and actions are described below. The quadriceps femoris is so called because it consists of four parts. These are the rectus femoris, the vastus lateralis the vastus medians. and the vastus intermedius. The rectus femoris is fusiform. It runs more or less vertically on the front of the thigh superficial to the vasti. The three vasti are wrapped around the shaft of the femur in the positions indicated by their names. The attachments of the components of the quadriceps femoris are given in Table 3.1. Their nerve supply and actions are given below.

The articularis genu consists of few muscular slips that arise from the anterior surface of the shaft of the femur, a few centimeters above the patellar articular margin. They are inserted into the upper part of the synovial membrane of the knee joint. They pull the synovial membrane upwards during extension of the knee, thus preventing damage to it.

                                                      nerve supplay 

All muscles of the anterior compartment of the thigh are supplied by the femoral nerveas

  Actions               The sartorius is an abductor and lateral rotator of the thigh. and flexor of the leg. All these actions are 

 involved in assuming the position in which tailors sit and work, i.e. the 'palthit posture (Sartor = tailor). The quadriceps is a strong extensor of the knee joint. This action is very important in standing, walking and running. In addition. the rectus femoris flexes the hip joint along with the iliopsoas and helps to maintain the erect attitude; and the vastus medialis prevents lateral displacement of the patella. The muscle is tested by attempting to extend the knee joint against resistance and palpating the contracting quadriceps muscle .

                                 lliacus and Psoas Major 

These muscles form the lateral part of the floor of the femoral triangle. They are classified as muscles of the iliac region, and also among the muscles of the
posterior abdominal wall. Since the greater parts o their fleshy bellies lie in the posterior abdomina wall, they will be described in detail in the section oz the abdomen. However on account of their principa action on the hip joint, the following points may bi noted. 1. Both have a common insertion on the lesse trochanter of the femur and are the chief and powerfu flexors of the hip joint. 2. Because of their common insertion and action the two muscles are often referred to by a commm name, the iliopsoas. 3. Both are supplied by spinal segments L2 am L3. The psoas is supplied by the branches from the nerve roots, whereas the iliacus is supplied by thi femoral nerve.

MuscleOrigin fromInsertion intoSarforius
2. Quadriceps lemoris A. Rectus lemons Fusdorm, superficial fibres bipennate, deep fibres straighta Vastus lateralis Forms large part of quadriceps lemonsC. Vastus mediaksD. Vastus interned usa. Anterior superior iliac spine and b. Upper half of the notch below the spine
a Straight head: from the upper half of the anterior inferior iliac spine b. Reflected head: from the groove above the margin of the acetabulum and the capsule of the hip joint
The origin is linear The line runs along:a. Upper part of the medial surface of the shah of the tibia in front of the insertions of the gracilis and the semitondinosusBase ol patella
a. Upper part of intertrochanteric rine a. Lateral part of the base of patella b. Anterior and Inferior borders of greater Irochanter b. Upper one-third of the lateral border of patella c. Lateral lip of gluteal tuberosity c. Expansion to the capsule of knee d. Upper half ol lateral lip of I inea aspera joint. tibia and iliotibial tract
The origin in linear. The tine runs along: a. Lower part of intertrochanteric line b. Spiral line c. Medial lip of lined aspera d. Upper one-fourth of medial supracondylar line
a. Upper three-fourths of the anterior and lateral surfaces of the shaft of femur
Medial one-third of the base and upper two-thirds of the medial border of the patella
Base of patella Note. The patella is a sesamoid bone in the tendon of the quadricep femoris. The ligamentum patellae is the actual tendon of the quadriceps femoris, which is inserted to the tibial tuberosity