hipanat

The pelvis is formed by two innominate bones, each one is comprised of the ilium, ischium and the pubis. The acetabulum is the depression or fossa where the femoral head articulates. It is positioned in a downward and outwardly direction. It is surrounded by a labrum much like the gleno humeral joint of the shoulder. The labrum is thicker and more substantial superiorly than inferiorly which corroborates with the weight bearing nature of the joint.

Anterior Superior Iliac Spine (ASIS)

Iliac Crest

Posterior Superior Iliac Spine (PSIS)

Ischial Tuberosity

SI Joint(s)

The posterior portion of the pelvic girdle is formed by the articulation with the sacrum. The Sacro-Iliac joint (SI) is a bilateral joint that fixates the spinal column to the pelvis. The articular surfaces of the SI joint are very irregular and when correctly matched with their articulating facets, makes a very stable joint.

The hip is the largest and most stable of the joints in the body. It is a multi axial ball and socket type joint. It has a very strong capsule and muscular control.

The acetabulum is formed by the fusion of the ilium, ischium, pubis and deepened by a acetabular labrum much like a shoulder. The positioning of the acetabulum is outward, forward and downward. It allows approximately 3⁰ of freedom of movement in multi axial directions.

The femoral head is globular and is approximately one half (2) hemispherical in nature. The articular surface is covered with a thick articular cartilage except at the center where the ligamentum teres connects. The femur connects to the head via the femoral neck. The normal angle of inclination is approximately 135⁰. This angle is somewhat decreased in women and thus leads to the overall Q angle changes. The angle of torsion is the forward angle relationship of the head and neck. The angle of anteversion ( torsion) is normally in the 12-15⁰ range.

Distal to the femoral neck on the shaft of the femur is the lateral projecting greater trochanter and the medial projecting lesser trochanter. These sites serve as primary attachment points for the pelvic and hip musculature.

The pelvic bones articulate anteriorly at a fairly immobile joint, the pubis symphysis. This is formed by the fibrocartilaginous interpubic disk. The movements that occur at this joint are small, but very necessary. They include spreading, compression and rotation. The posterior articulations occur at the SI joint.

This joint is part synovial and part syndesmosis. The syndesmosis is a fibrous joint where the tissues form the ligament or membrane that provides the stability. No muscles cross the SI joint. The size, stability and associated roughness of the joint vary from patient to patient.

This joint becomes progressively inflexible as the patient ages. The movements that occur in the SI joint are minute when compared to other joint motions. However, they are often very painful if moved to extremes due to the roughness of the joint surfaces.

Contranutation - this movement occurs at the SI joint. It is characterized by an anterior rotation of the innominate on the affected side and posterior rotation of the sacrum on the ilium on the opposite side. The ASIS on the affected side will be lower, while the PSIS on the contralateral side will be higher. (position of lordosis)

Nutation - is the opposite of contranutation and is characterized by a backwards rotation of the innominate. The result will be a functional short leg on the affected side. (position of pelvic tilt)

Forward flexion of the spine (40-60⁰)
Extension of the spine (20-35⁰)
Rotation of the spine (30-18⁰)
Side flexion of the spine (15-20⁰)
Flexion of the hip (100-120⁰)
Abduction of the hip (30-50⁰)
Adduction of the hip (30⁰)
Medial rotation of the hip (30-40⁰)
Lateral rotation of the hip (40-60⁰)

The resting position of the hip occurs at 30⁰ of flexion, 30⁰ of abduction and slight internal rotation. The hip joint is loaded in the following manner;

standing - 1/3 of body weight
standing on one limb - 2-2.5x body weight
walking - 1.5 - 5.5x body weight
walking stairs - 3x body weight
running - 4.5x > body weight depending upon the ability of the runner and the type of running to be performed.

Flexion - 110-120⁰Extension - 10-15⁰Abduction - 30-50⁰Adduction - 30⁰Lateral rotation - 40-60⁰Medial rotation - 30-40⁰


Flexors	Extensors

Hip flexor, makes up part of the quadriceps group. 2 joint muscle (knee and hip).

Flexes the knee, contributes to flexion, abduction and external rotation of the hip.

Iliopsoas Group

psoas major, psoas minor and iliacus make up this group. They are the primary hip flexors when the knee is extended and work with the rectus when the knee is flexed.

The rectus, sartorius and iliacus can all rotate the pelvis at the SI joint as they contract. Thus, tightness in the anterior hip flexors can lead to increased stress on the SI joint via anterior rotation of the pelvis.

Adductor group

adductor longus, adductor magnus, adductor brevis are all adductors of the thigh. These muscles are supplemented by the pectineus.

Gluteus Medius

Superficial lateral muscle, primary abductor of the hip. It is also important in maintaining the torsos position during gait. Weakness in the gluteus medius results in the torsos bending toward the affected side when the opposite leg is non weight bearing. The compensating movement is termed Trendelenburg's gait pattern. The tensor fascia latae is part of the iliotibial band and is an abductor an external rotator.

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Gluteus maximus is the powerful extensor of the hip especially when the knee is flexed.

The Hamstring group (semitendinosus, semimembranosus, biceps femoris) works as an extensor of the hip when the knee is extended. This group also performs the important task of decelerating hip flexion and knee extension during running via an eccentric contraction. The short head of the biceps femoris is not a true hamstring muscle since it is only a one joint muscle, however, it helps to initiate knee flexion and thus acts in conjunction with the true hamstring muscles.

This is formed by the inguinal ligament, the sartorius laterally and the adductor longus on the medial side. This is a clinical landmark that is used as a reference point and because of the underlying structures. Parts of the femoral nerve, artery and vein are located within this area. The femoral pulse is palpable here as well as the lymph nodes if there is an infection or inflammation in the lower extremity.

Three bursae are found in the hip and pelvic region. The bursae act to decrease friction between the gluteus maximus and the bony structures. The trochanteric bursae lubricates the site at where the maximus passes over the greater trochanter, the gluteofemoral bursae separates the maximus and the vastus lateralis and the ischial bursae serves as a weight bearing structure when the patient is sitting.


Nerves of the Thigh

The sciatic nerve is located midway between the greater trochanter and the ischial tuberosity. When the hip is extended. The nerve is covered by the gluteus maximus, when flexed, the maximus moves out of the way. Palpate by going half way between the tuberosity and the greater trochanter.

The rectus femoris muscle may avulse from the the ASIS on the iliac crest. This condition will most likely occur in adolescent aged athletes.

Described by some in the literature as the "ultimate" hip pointer, this is a stable fracture but will remain quite sore for an extended period of time.

The hamstrings have their proximal attachment on the ischial tuberosity. Adolescent athletes that experience point tenderness over the proximal attachment should be carefully examined. While x-rays will help confirm the presence of the avulsion, the treatment remains the same. However, the practitioner will know that the recovery will be delayed. The patient will likely complain of increased pain while seated. This finding may be exacerbated as the avulsion heals with the associated bony callus formation.

Pelvic fractures involving the complete pelvic girdle require great amounts of trauma and external forces usually found associated with MVA's, motorcycling, horseback riding and some extreme sports. The "open book" pelvis fracture in which the pelvis is split open from the front has been seen with rodeo athletes.

Femoral neck stress fractures are often associated with overuse. Bone scans and MRI's are useful for assessment of this condition. Deep bony pain that is located only on one side of the body should be carefully examined.


Bone scan showing positive rt. femoral neck stress fracture	MRI showing inferior femoral neck stress fracture

This patient was a 24 y.o. female, former NCAA Division I Cross Country runner that complained of deep groin pain as well as nocturnal pain. she was treated with a 3 month period of rest that progressed through non weight bearing, partial weight bearing and then to full weight bearing. She was then progressed in a rehab protocol that involved walking, water walking and water running and finally a resumption of non competitive levels of running.

Also referred to as a "Pipkin" fracture, these occur primarily in association with hip dislocations.

Fairly uncommon in occurrence, however, this injury is more frequently seen in younger aged athletic participants as well as high energy level trauma situations.

Hip fractures will almost always present with the hip flexed and the femur externally rotated while dislocations will present with the hip flexed and the femur internally rotated.

The cluneal nerves pass over the mid posterior portion of the iliac crest and supply sensation to the skin. These nerves are significant when dealing with blunt trauma to the crest as you would find with a hip pointer type injury. These nerves are also commonly cut when a bone graft is taken.

Prior medical information is important because of congenital or child hood abnormalities can result in altered biomechanics. These conditions would include Legg Calve Perthes Disease or a slipped capital femoral epiphysis. (SCFE)

Legg Calve Perthes Disease - avascular necrosis occurring in children are 3 to 12 years causing osteochondritis of the proximal femoral epiphysis.

Slipped capital femoral epiphysis (SCFE) - displacement of the head relative to the femoral shaft common in boys aged 10-15. Primarily is prevalent in overweight and in persons with Hispanic heritage. These patients most frequently present with knee pain. Always check hip function in young patients.

Avascular Necrosis of the Femoral Head (AVN)

The head of the left femur shows a dark area on each view. This represents dead bone or bone that no longer has any blood supply. This requires a total hip replacement orthosis.

AVN of the hip is frequently associated with dislocations, displaced femoral neck fractures, in patients that have used catabolic steroids, alcoholics and idiopathic AVN in which the cause is never determined.

Thomas Test (for hip flexor tightness)
Fabere Sign or Patrick's (Test for SI joint pain)
Trendelenburg's sign tests for the function of the hip abductors to stabilize the pelvis on the femur.
Ober Test for IT band tightness

Leg length must be evaluated -
True leg length is measured from the ASIS to the distal tip of the medial malleolus.
Apparent leg length is measured from the Umbilicus to the distal tip of the medial malleolus. Discrepancies of less than 3/4" are not usually significant.

Lack of flexibility

Muscle Imbalance
quad to quad ratio 10% variance bilaterally, 5 % normal
quad to hamstring ratio low speed 75% quad to hams
high speed 100% quad to hams

Trunk inflexibility

Fatigue which often presents as an eccentric loaded injury.


Notice the deficit in the Rt. Hamstring as noted by the finger pointer.	This athlete had immediate pain that was followed by a 7-10 period of localized pain at the origin site on the Ischial tuberosity. The represents a partial avulsion type injury. This picture is 1 month post injury.

Groin Strains - Most "groin" strains are simply pulls to the adductor group, some can be more involved as with this deep adductor avulsion of the pectineus muscle.


Pectineus Muscle Avulsion


These pictures represent AVN, Avascular Necrosis of the Head of the Femur. This is a disease that occurs infrequently but is very serious when it does. This is the "Bo Jackson" injury that took him out of football and baseball.