Chapter 18 Hip joint
Ischium
"Sit bones" Is the posterior inferior portion of the innominate bone.
Iliopsoas muscle
-On the anterior surface -One joint muscle Origin: Iliac fossa, anterior and lateral surfaces of T12 through L5 Insertion: Lesser trochanter Action: Hip flexion Nerve: Iliacus portion: femoral nerve (L2,L3) Psoas major portion: L2 and L3
Gluteus minimus muscle
-One joint - The smallest and deepest of the three gluteal muscles, the gluteus minimus muscle lies deep and inferior to the gluteus medius muscle on the lateral ilium. Its broad proximal attachment extends from near the greater sciatic notch to almost as far forward as the anterior border, near the ASIS. The distal attachment is on the anterior aspect of the greater trochanter. This gives the gluteus minimus muscle a somewhat diagonal line of pull, making it able to medially rotate the hip. Because it spans the hip joint laterally it also abducts the hip. O: lateral surface of the iliumm I: Anterior surface of the greater trochanter A: Hip abduction, medial rotation N: Superior gluteal nerve (L4,L5,S1)
Tensor fascia lata muscle
-Two joint muscle -Is a very short muscle with a very long tendinous attachment. It arises from the ASIS, crosses the hip joint laterally and slightly anteriorly, and then attaches to the long fascial band called the iliotibial band, which proceeds down the lateral thigh and attaches to the lateral condyle of the tibia. IT is a hip abductor, but due to its slight anterior position, it is perhaps strongest when performing a combination of flexion and abduction. O: ASIS I: Lateral Condyle of Tibia A: Combined hip flexion and abduction N: Superior gluteal nerve (L4,L5,S1)
Piriformis muscle
-the piriformis is the best known of this group perhaps because of its close relationship to the sciatic nerve - Tighteness of the piriformis can compress the sciatic nerve resulting in radiating pain down the back of the leg.
Lesser Trochanter Bony landmarks of the Femur
A smaller projection located medially and posteriorly just distal to the greater trochanter, providing attachment for the iliopsoas muscle
Describe the hip joint: A: number of axes: B: shape of joint: Type of motion allowed:
A: 3 B:Ball and socket C: flexion/extension, abduction/adduction, and rotation
Regarding the statement "hanging on the Y ligaments" A: What position are the hips in relative to the shoulders? B: Where does the line of gravity fall relative to the shoulders? C: Gravity exerts a force that wants to move the hip into __________ D: This strategy is most helpful when the hip _____ muscles group is weak.
A: Anterior/ hips are in extension B: Posterior C: Extension D: Extensor
What motions occur in: A: the transverse plane around the vertical axis? B: the sagittal plane around the frontal axis? C: the frontal plane around the sagittal axis?
A: Medial and lateral rotation B: Flexion/extension C: Abduction/adduction
Hip muscles can be grouped according to
According to their location and somewhat by their function. For example the anterior muscles with a vertical line of pull tend to be flexors, lateral muscles tend to be abductors, posterior muscles tend to be extensors, and medial muscles tend to be adductors. Muscles that have a more horizontal line of pull and cross the anterior side of the hip are medial rotators and those that cross the posterior side of the hip are lateral rotators.
Bones that make up Hip Joint
Acetabulum of the innominate and head of the femur
Pubis
Forms the anterior inferior portion of the innominate bone. It can be divided into three parts-the body and its two rami.
Semitendinosus muscle
Has a much longer and narrower distal tendon that psans the knee joint posteriorly and then moves anteriorly to attach to the anteromedial surface of the tibia with the gracilis and sartorius muscles. O: Ischial tuberosity I: Anteromedial surface of proximal tibia A: Hip extension and knee flexion N: Sciatic nerve- tibial division (L5,S1,S2) Two joints
Bicep femoris muscle
Has two heads and runs down the thigh laterally on the posterior side. The long head arises with the other two hamstring muscles on the ischial tuberosity, but the short head arises from the lateral lip of the linea aspera of the femur. Both heads join together, spanning the knee posteriorly to attach laterally on the head of the fibula and, by a small slip, to the lateral condyle of the tibia. Because they span the knee posteriorly they flex the knee. The long head, because it spans the hip joint posteriorly, extends the hip. O: Long head: Ischial tuberosity Short head: lateral lip of linea aspera I: fibular head a: Long head: hip extension and knee flexion Short head: knee flexion N: Long head: sciatic nerve- tibial division (L5,S1,S2) Short head: common fibular (peroneal) nerve (L5,S1,S2) Two joints
What is the end feel of hip flexion? Hip extension?
Hip flexion-soft Hip extension-firm
The end feel of all hip joint motions except flexion is what?
IS firm because of tension in the capsule, ligaments, and muscles. For hip flexion the end feel is soft because of contact between the anterior thigh and the abdomen.
LEgg-Calve-Perthes disease or coxa plana
Is a condition in which the femoral head undergoes necrosis. It is usually seen in children between the ages of 5 and 10 years. During the course of the disease, it may take about 2 to 4 years for the head to die, revascularize and then remodel.
Coxa vara
Is a deformity in which the neck-shaft angle is less than the normal 125 degrees. Because it is "more bent" it tends to make the involved limb shorter, dropping the pelvis on that side during weight-bearing.
Osteoarthritis
Is a degeneration of the articular cartilage of the joint. It may result from trauma or wear and tear and is typically seen later in life. It is commonly treated with a total joint replacement.
Hip pointer
Is a misnomer because it occurs at the pelvis not the hip joint It is a severe bruise caused by direct trauma to the iliac crest of the pelvis. It is most commonly associated with football but can be seen in almost any contact sport. Spearing the hip/pelvis with a helmet while tackling may be the most common cause.
Rectus femoris muscle
Is a part of the quadriceps muscle group and is the only one of that group to cross the hip joint. It's proximal attachment is on the AIIS Anterior muscle, two joint O: AIIS I: Tibial tuberosity Action: hip flexion, knee extension Nerve: Femoral nerve (L2,L3,L4)
Iliopsoas
Is actually two muscles with separate proximal attachments and a common distal attachment. The iliacus muscle portion arises from the iliac fossa, and the psoas major muscle portion comes from the transverse processes, bodies, and intervertebral disks of the T12 through L5 vertebrae. These muscles blend together to attach on the lesser trochanter of the femur. -Prime mover in hip flexion -Because of its attachment on the vertebrae, the Psoas muscle portion contributes to trunk flexion when the femur is stabilized.
Iliotibial band syndrome
Is an overuse injury causing lateral knee pain. It is commonly seen in runners and bicyclist. This syndrome is believed to result from repeated friction of the band that slides over the lateral femoral epicondyle during knee motion. It is caused by such factors as muscle tightness, worn down shoes, and running on uneven surfaces.
Coxa valga
Is characterized by a neck-shaft angle greater than 125 degrees. Because the angle is "straigther" it tends to make the limb longer, thus placing the hip in an adducted position during weight- bearing.
Innominate bone
Is irregularly shaped and actually consists of three bones- the ilium, the ischium, and the pubis. By adulthood, these bones fuse together
Slipped capital femoral epiphysis
Is seen in children during the growth spurt tears. The proximal epiphysis slips from its normal position on the femoral head
Femur
Is the longest, strongest, and heaviest bone in the body. A persons height can roughly be estimated to be four times the length of the femur. It articulates with the innominate bone to form the hip joint and has significant landmarks.
Hip joint
Is the most proximal of the lower extremity joints. It is very important in weight-bearing and walking activities. Like the shoulder, it is a ball-and-socket joint. The rounded, or convex-shaped femoral head fits into and articulates with the concave shaped acetabulum. The convex femoral head slides in the direction opposite the movement of the thigh. Unlike the shoulder, the hip is a very stable joint and therefore sacrifices some range of motion.
Trochanteric bursitis
Is the result of either acute trauma or overuse. It can be seen in runners or bicyclists or in someone with a leg length discrepancy, or it can be caused by other factors that put repeated stress on the greater trochanter.
Iliotibial band or tract
Is the very long, tendinous portion of the tensor fascia lata muscle. It attaches to the anterior portion of the iliac crest and runs supericially down the lateral side of the thigh to attach to the tibia. Both the gluteus maximus and tensor fascia lata muscles have fibers attaching to the iliotibial band.
Gluteus medius muscle
Is triangular much like the deltoid muscle of the shoulder. It attaches proximally to the outer surface of the ilium and distally to the lateral surface of the greater trochanter. Because it spans the hip joint laterally, the gluteus medius muscle can abduct the hip. Its anterior fibers are able to assist the gluteus minimus muscle in medially rotating the hip. O: Outer surface of the ilium I: Lateral surface of the greater trochanter A: Hip abductions N:Superior gluteal nerve (L4,L5,S1) One joint
What kind of joint is the hip joint?
It is a triaxial joint, the hip has motion in all three planes. -Flexion, extension, and hyperextension occur in the sagittal plane with approximately 120 degrees of flexion and 15 degrees of hyperextension. Extension is the return from flexion. -Abduction and adduction occur in the frontal plane, with about 45 degrees of abduction. Adduction is usually though of as the return to anatomical position, although there is approximately an addition 25 degrees of motion possible beyond the anatomical position. -In the transverse plane medial and lateral rotations are sometimes referred to as internal and external rotation. There are approximately 45 degrees of rotation possible in each direction from the anatomical position.
Posterior Superior Iliac Spine (PSIS) Bony landmarks of the Ilium
It is the posterior projection on the iliac crest
Greater sciatic notch made up of combination of the innominate bones
Large notch just below the PIIS that is actually made into a foramen by the sacrospinous and sacrotuberous ligaments. The sciatic nerve, piriformis muscle, and other structures pass through this opening.
Tibial Tuberosity
Large projection at the proximal end, in the midline. It provides attachment for the patellar tendon.
Greater trochanter Bony landmarks of the Femur
Large projection located laterally between the neck and the body of the femur, providing attachment for the gluteus medius and minimus and for most deep rotator muscles.
Iliac fossa Bony landmarks of the Ilium
Large, smooth, concave area on the internal surface to which the iliac portion of the iliopsoas muscle attaches
Inferior Ramus Bony landmarks of the Pubis
Lies posterior, inferior, ad lateral to the body. Provides attachment for the adductor magnus and brevis and gracilis muscles.
Superior Ramus Bony landmarks of the Pubis
Lies superiorly between the acetabulum and the body and provides attachment for the pectineus muscle.
Hip joint capsule
Like all synovial joints the hip has a fibrous joint capsule. It is strong and thick and it covers the hip joint in a cylindrical fashion. It attaches proximally around the lip of the acetabulum and distally to the neck of the femur. It forms a cylindrical sleeve that encloses the joint and most of the femoral neck.
Hip has one and two joint muscles
Like the shoulder, the hip has a group of one joint muscles that provide most of the control, and it has a group of longer, two-joint muscles that provide the range of motion.
Patellar surface Bony landmarks of the Femur
Located between the medial and lateral condyle anteriorly. It articulates with the posterior surface of the patella.
Posterior Inferior Iliac Spine (PIIS) Bony landmarks of the Ilium
Located just below the PSIS
Ischial Spine Bony landmarks of the Ischium
Located on the posterior portion of the body between the greater and lesser sciatic notches. It provides attachment for the sacrospinous ligament.
Ischial body Bony landmarks of the Ischium
Makes up about two-fifths of the acetabulum
Ilium
Makes up the superior portion of the innominate bone.
Adductor brevis muscle
Medial muscle, one joint O: Pubis I: Pectineal line and proximal linea aspera A: Hip adduction N: Obturator nerve (L2,L3)
Adductor longus muscle
Medial muscle, one joint O: Pubis I: middle third of the linea aspera A: hip adduction N: obturator nerve (L2,L3,L4)
Pectineus muscle
Medial muscle, one joint O:Superior ramus of pubis I: Pectineal line of femur Action: Hip flexion and adduction Nerve: Femoral nerve (L2,L3)
Trochanteric Fossa Bony landmarks of the Femur
Medial surface of the greater trochanter
Adductor magnus muscle
O: Ischium and pubis I: Entire linea aspera and adductor tubercle A: Hip adduction N: Obturator and sciatic nerve (L2,L3,L4) The largest and deepest of the adductors
Gracilis muscle
O: Pubis I: anteromedial surface of proximal end of tibia A: Hip adduction N: obturator nerve (L2,L3)
Congenital hip dislocation or dysplasia
Occurs when an unusually shallow acetabulum causes the femoral head to slide upward. The joint capsule remains intact, though stretched.
Does the femoral head surface glide in the same or opposite direction as the thigh during hip flexion/ extension?
Opposite
Gluteus maximus muscle
Posterior, one joint CAn be described as a large, thick, one-joint, quadrilateral muscle located superficially on the posterior buttock. O: Posterior sacrum and ilium I: posterior femur distal to greater trochanter and to iliotibial band A: Hip extension, hyperextension, lateral rotation N: Inferior gluteal nerve (L5,S1,S2)
Lateral epicondyle of femur Bony landmarks of the Femur
Projection proximal to the lateral condyle
Medial epicondyle of femur Bony landmarks of the Femur
Projection proximal to the medial condyle (epi means on top)
Pubic tubercle Bony landmarks of the Pubis
Projects anteriorly on the superior ramus near the symphysis pubis and provides attachment for the inguinal ligament
Linea aspera Bony landmarks of the Femur
Prominent longitudinal ridge or crest running down the middle third of the posterior shaft of the femur to which many muscles attach
Piriformis One of the six deep rotator muscles
Proximal Attachment: Anterior Sacrum Distal Attachment: Medial surface of greater trochanter Innervation:L5,S1,S2
Obturator Externus One of the six deep rotator muscles
Proximal Attachment: External surface of inferior two thirds of obturator foramen Distal Attachment: Trochanteric fossa Innervation: Obturator nerve
Obturator internus One of the six deep rotator muscles
Proximal Attachment: Internal surface of most of obturator foramen Distal Attachment: Trochanteric fossa Innervation: Obturator nerve
Gemellus superior One of the six deep rotator muscles
Proximal Attachment: Ischial spine Distal Attachment: Medial surface of greater trochanter Innervation: Nerve to obturator internus
Quadratus femoris One of the six deep rotator muscles
Proximal Attachment: Ischial tuberosity Distal Attachment: Intertrochanteric crest Innervation: Nerve to quadratus femoris
Gemellus inferior One of the six deep rotator muscles
Proximal Attachment: Ischial tuberosity Distal Attachment: Medial surface of greater trochanter Innervation: Nerve to quadratus femoris
Ischial tuberosity Bony landmarks of the Ischium
Rough, blunt projection of the inferior part of the body, which is weight bearing when you are sitting. It provides attachment for the hamstring and adductor magnus muscles.
Semimembranosus muscle
Runs down the medial sidle of the thigh, deep to the semitendinosus muscle, and inserts on the posterior surface of the medial condyle of the tibia. O: Ischial tuberosity I: posterior surface of medial condyle of tibia A: Hip extension and knee flexion N: Sciatic nerve- tibial division (L5,S1,S2) Two Joints
Pectineal line Bony landmarks of the Femur
Runs from below the lesser trochanter diagonally toward the linea aspera. IT provides attachment for the adductor brevis.
Adductor tubercle Bony landmarks of the Femur
Small projection proximal to the medial epicondyle to which a portion of the adductor magnus muscle attaches.
Hip fractures
Tend to be two types: Intertrochanteric and femoral neck These are very common among elderly people, usually resulting from falls. High impact trauma such as motor vehicle accidents may cause hip fractures in younger individuals.
Why is the hip joint not prone to dislocation?
The acetabulum forms a deep socket holding most of the femoral head, and the joint is surrounded by three very strong ligaments
Adductor Hiatus
The adductor hiatus is the gap or opening in the distal attachment of the adductor magnus between the linea aspera and the adductor tubercle. It is significant because the femoral artery and vein pass through this opening to reach the posterior surface of the knee, where their name changes to politeal artery and vein.
Angle of inclination
The angle between the shaft and the neck of the femur in the frontal plane is referred to as the angle of inclination which normally is 125 degrees. Thing angle varies from birth to adulthood. At birth the angle may be as great as 170 degrees but by adulthood the angle decreases significantly.
Angle of torsion
The angle between the shaft and the neck of the femur in the transverse plane is called the angle of torsion which normally has the head and neck rotated outward from the shaft approximately 15 to 25 degrees.
Acetabular labrum
The depth of the acetabulum is increased by the fibrocartilaginous acetabular labrum, which is located around the rim. The free end of the labrum surrounds the femoral head and helps to hold the head in the acetabulum.
What is referred to as the Y ligament? Why?
The distal attachment of the iliofemoral ligament; because it splits into two parts, forming an upside-down Y
Bones that make up Innominate
The fused bones of the ilium, ischium, and pubis
Bones that make up Pelvis
Two innominate bones, the sacrum, and the coccyx
Trendelenburg gait
Weakness or loss of these muscles (glute medius and minimus) results in this
What muscles keep your pelvis from dropping on one side when you lift one foot off the floor? Describe what happens
When you lift your right foot off the floor, the left hip abductors and right trunk extensors contract to keep the right side of the pelvis from dropping. A force couple exists when the hip abductors are pulling down while the trunk extensors are pulling up.
What two muscles contract to keep the pelvis fairly level?
When you stand on one leg the gluteus medius and minimus muscles contract to keep the pelvis fairly level and to prevent the opposite side of the pelvis from dropping too much (lateral tilt) when you stand on one leg. This occurs every time you pick up one leg, as when walking.
How would you determine whether an unattached femur is a right or left one?
With the femur in the vertical position, the linea aspera and lesser trochanter are posterior, and the head faces medially. Therefore, in this position the head of the right femur faces towards the left.
If you were handed an unattached innominate bone, what landmarks would you use to determine whether it was a right or left bone?
With the greater sciatic notch posterior an the body of the pubis anterior, the acetabulum faces laterally. Therefore if the acetabular opening is facing to the right in this position, it is a right innominate bone.
How many and what ligaments reinforce the hip joint capsule?
3 The iliofemoral, the pubofemoral, and the ischiofemoral ligaments.
Symphysis Pubis Bony landmarks of the Pubis
A cartilaginous joint connecting the bodies of the two pubic bones at the anterior midline.
Retroversion
A decrease in the angle of torsion is called this. This forces the hip joint into a more laterally rotated position, causing the person to walk more "toed out"
Acetabulum made up of combination of the innominate bones
A deep, cup-shaped cavity that articulates with the femur. It is made up of nearly equla portion of the ilium,ischium,and pubis.
Obturator Foramen made up of combination of the innominate bones
A large opening surrounded by the bodies and rami of the ischium and pubis and through which pass blood vessels and nerves
Hamstring strain
Also called a pulled hamstring is probably the most common muscle problem in the body. Unfortunately it is often recurrent. It may result from an overload of the muscle or trying to move the muscle too fast. Therefore, this is a common injury among sprinters and in sports that require bursts of speed or rapid acceleration such as soccer, track and field, football,baseball, and rugby. Hamstring strains can occur at one of the attachment sites or at any point along the length of the muscle.
Inguinal ligament
Although the inguinal ligament has no function at the hip joint, it should be identified because of its presence. It runs from the ASIS to the pubic tubercle and is the landmark that seperates the anterior abdominal wall from the thigh. When the external iliac artery and vein pass under the inguinal ligament, their names change to the femoral artery and vein.
If hip lateral rotation was limited, the femoral head is restricted from gliding in the _______ direction.
Anterior
Sartorius muscle
Anterior muscle and two joint muscle O: ASIS I: Proximal medial aspect of tibia A: Combination of hip flexion, abduction, lateral rotation, and knee flexion Nerve: Femoral nerve (L2,L3)
All three hip joint ligaments that reinforce the capsule
Attach along the rim of the acetabulum and cross the hip joint in a spiral fashion to attach on the femoral neck. The combined effect of this spiral attachment is to limit motion in one direction (hyperextension) while allowing full motion (flexion) in the other direction. Therefore, these ligaments are slack in flexion and become taut as the hip joint moves into hyperextension. If you thrust your hips forward so that they are in front of the shoulders and knees, you cause the line of gravity (LOG) to pass posterior to the axis of rotation for the hip joint. This allows you to stand in the upright postion without using any muscles by essentialy resting or hanging on the iliofemoral ligament. -This is the basis for the standing posture of an individual with paralysis following spinal cord injury.
Thigh Bones of the lower extremity:
Bones- Femur and Patella
Pelvis Bones of the lower extremity:
Bones- Innominate, sacrum, coccyx Individual Bones- Ilium (top), ischium (sit bones), and pubis (front bottom)
Foot Bones of the lower extremity:
Bones-Tarsals (7) Metatarsals (5) Phalanges (14) Individual bones- Tarsals- calcaneus,talus,cuboid, navicular, and cuneiform(3) Metatarsals-first through fifth Phalanges(14)- Proximal (5), middle (4), and distal (5)
Leg Bones of the lower extremity:
Bones: Tibia and fibula
Iliac crest Bony landmarks of the Ilium
Bony part that your hands rest on when you put your hands on your hips. Its borders are the anterior superior iliac spine and the posterior superior iliac spine.
Lateral condyle of femur Bony landmarks of the Femur
Distal lateral end
Medial Condyle of femur Bony landmarks of the Femur
Distal medial end
Ischial Ramus Bony landmarks of the Ischium
Extends medially from the body to connect with the inferior ramus of the pubis. The adductor magnus, obturator externus, and obturator internus muscles attach here.
Pubic Body Bony landmarks of the Pubis
Externally forms about one-fifth of the acetabulum and internally provides attachment for the obturator internus muscle
Bones that make up Greater Sciatic Notch
The ilium and ischium
Bones that make up Acetabulum
The ilium, ischium, and pubis
Bones that make up Obturator Foramen
The ischium and pubis
What is the direction of the line of attachment of the hip ligaments--- vertical, horizontal, or spiral? What does this line of attachment allow for?
The line of attachment of the ligaments is a spiral. This arrangement causes the ligaments to become taut as the joint moves into extension and to slacken with flexion, thus limiting hyperextension without impeding flexion
Body of Femur Bony landmarks of the Femur
The long, cylindrical portion between the bone ends; also called the shaft. It is bowed slightly anteriorly.
Iliofemoral ligament
The most important of these ligaments in the hip joint capsule. It reinforces the capsule anteriorly by attaching proximally to the AIIS and crossing the joint anteriorly. It splits into two parts distlly to attach to the intertrochanteric line of the femur. Because it resembles an inverted Y, it is often referred to as the Y ligament. It is also known as the ligament of Bigelow. Its main function is to limit hyperextension.
Neck of femur Bony landmarks of the Femur
The narrower portion located between the head and the trochanter
Anterior Superior Iliac Spine (ASIS) Bony landmarks of the Ilium
The projection on the anterior end of the iliac crest. The tensor fascia lata and sartorius muscles and the inguinal ligament attach here.
Anterior Inferior Iliac Spine (AIIS) Bony landmarks of the Ilium
The projection to which the rectus femoris attaches is on the AIIS
Which two joint hip muscles attach below the knee?
The rectus femoris, sartorius, gracilis, semitendinosus, semibranosus, biceps femoris (long head), and tensor fascia latae muscles.
Head of Femur Bony landmarks of the Femur
The rounded portion covered with articular cartilage articulating with the acetabulum
Which hip joint muscles are not prime movers in any single action but are effective in a combination of movements? List the movements.
The sartorius muscle is involved in hip flexion, abduction, and lateral rotation; the tensor fasciae latae muscle is involved in flexion and abduction
Anteversion
The shaft is best known here by a line through the femoral condyles, which attach to the shaft distally. As the shaft roates, so do the condyles. An increase in this angle is called anteversion which forces the hip joint into a more medially rotated position. This causes a person to walk more toed in.
Intertrochanteric Crest Bony landmarks of the Femur
The smooth ridge between greater and lesser trochanters. Serve as attachment for quadratus femoris.
Pelvic girdle or Pelvis
The two innominate bones are connected to each other anteriorly and to the sacrum posteriorly. The sacrum is also connected distally to the coccyx.
Deep rotator muscles
There are six small, deep, mostly posterior muscles that span the hip joint in a horizontal direction, and they all laterally rotate the hip. Because they all work together to produce the same motion, their individual attachments are not functionally important; therefore, they can be grouped together as the deep rotator muscles. -However the piriformis is the best known of this group perhaps because of its close relationship to the sciatic nerve O: Anterior sacrum, ischium, pubis I: Greater trochanter area A: Hip lateral rotation N: Numerous
Ischiofemoral ligament
This ligament covers the capsule posteriorly. It attaches on the ischial portion of the acetabulum, crosses the joint in a lateral and superior direction, and attaches on the femoral neck. Its fibers limit hyperextension and medial rotation.
Pubofemoral ligament
This ligament spans the hip joint medially and inferiorly. It attaches from the medial part of the acetabular rim and superior ramus of the pubis and runs down and back to attach on the neck of the femur. Like the iliofemoral ligament, it limits hyperextension. In addition it limits abduction.
Hamstring muscles
Three muscles that cover the posterior thigh. They consist of the semimebranosus, the semitendinosus, and the biceps femoris muscles. They have a common site of origin on the ischial tuberosity.
