1
p.177 2
3
The psoas minor is medial to the psoas major. The iliacus is a fan-shaped muscle that when contracted helps bring the swinging leg forward in walking and running. The iliopsoas and adductor thigh group muscles coming up on the next few slides are involved when you pull your groin or have a groin strain. The iliopsoas is able to obtain external rotation since it inserts into the lesser trochanter of the femur, which is located on the posterior side. The iliopsoas and psoas minor are commonly referred to as the true groin muscles (hip flexor muscle group): the term groin refers to the anterior aspect of the hip joint. The medial muscles of the hip joint are often referred to as the common groid muscles (hip adductor muscle group). These muscles also help to flex the vertebral column. p.178 4
The sartorius is the longest muscle in the body and is also called the tailor s muscle because it is used when you sit with your leg crossed on top of the other leg, which is how tailors typically sit. It is also used when sitting in the yoga style position. The sartorius is superficial and crosses over the top of the thigh to the upper, medial part of the tibia. p.179 5
p.179 6
The pectineus is a medial muscle and the most superior of the adductor group (adductor brevis, longus, magnus) that comes off of the pubic bone. Remember the pectineal line is the small line from the lesser trochanter to the linea aspera on the posterior side of the femur. And since the pectineus inserts there that is how it got its name. p.180 7
The adductor brevis lies deep to the adductor longus. The adductor muscle group is important in activities that require you to press your thighs together, such as horseback riding. The adductor longus is the most anterior of the adductor muscles and helps form the medial border of the femoral triangle. p.183 8
9
The adductor magnus is located anterior and posterior. Notice the origin is still on the pubis which is anterior, but it also has an origination point on the ischium which is posterior. So the more anterior part of the adductor magnus can do hip adduction, flexion, and external rotation. The posterior part can do extension (hyperextension) and internal rotation. This is the largest muscle of the adductor group. Remember the adductor tubercle lies just above the medial epicondyle of the femur. And since the adductor magnus inserts into the adductor tubercle, its name makes sense. p.183 10
The adductor group. So from off of the pubic bone from top to bottom: pectineus, adductor brevis, adductor longus, and adductor magnus. 11
The gracilis is the long, thin, superficial muscle on the inside of your thigh and is the most medial muscle of the thigh. The gracilis also adducts the hip so it is part of the adductor muscle group. p.183 12
13
The biceps femoris is the most lateral of the 3 hamstring muscles. There are 2 heads (long & short head) and it inserts where the tibia and fibula come together. p.180 14
Semimembranosus is medial to the biceps femoris and lies deep to the semitendinosus. p.181 15
Semitendinosus sits on top of the semimembranosus. p.181 16
The gluteus maximus is your butt muscle. Notice the origination point on the ilium is more superior than the sacrum/coccyx origin. So the more superior part allows extension and external rotation, and the inferior part allows adduction, extension, and external rotation. The gluteus maximus has the important sciatic nerve running deep through it, which is why intramuscular injections are done in the gluteus medius to avoid the sciatic nerve in the gluteus maximus. The IT band stands for the iliotibial band, which is a tract of fascia/tissue. p.182 17
Intramuscular injections are done in the gluteus medius since it is more lateral and avoids the sciatic nerve. The gluteus medius and minimus are located more lateral than the gluteus maximus. The gluteus minimus lies deep to the gluteus medius and is just a smaller version of the medius. The gluteus muscles help maintain upright posture and are active during running, jumping, climbing, etc. The gluteus minimus is the smallest and deepest gluteal and it helps keep the pelvis level. p.185 18
The tensor fasciae latae is a short muscle with a long, tendinous band on the lateral side of your thigh. It helps to make the IT (iliotibial band) taut and stabilizes the hip and braces the knee when you are walking. The IT band inserts on the lateral condyle of the tibia. Runners may get IT Band Syndrome which is a painful injury that is felt on the lateral side of your thigh and knee from running. p.179-180 19
20
Remember the ischium is the posterior part of the pelvis and the greater trochanter is located on the lateral side of the femur which is how external rotation can occur from these 6 external rotator muscles. Know all 6 muscle names and their general origin and insertion. p.180 21
Overall, the Origin = ischium Insertion = greater trochanter Action = external rotation and stabilize the femur p.183 22