The structure of the hip joint consists of the acetabulum (socket) and the femoral head (ball). The acetabulum is the socket in the pelvis formed by three innominate bones: the ilium, the ischium and the pubis. The socket faces laterally and also slightly inferiorly and anteriorly.
The femoral head is roughly semispherical, with a short “neck of the femur” angling the head anteriorly, medially and superiorly to fit into the socket.
The angle of inclination is created by the head of the femur and the long bone of the femur. This angle is normally 125 degrees in adults, greater in infants. It may be slightly less than 125 degrees in women, owing to their wider pelvises.
The hip joint has three degrees of freedom; that is, it moves in three different planes:
1. sagittal plane: flexion/extension
2. frontal plane: abduction/adduction
3. transverse plane: external/internal rotation
The following structures stabilize the hip joint:
Ligaments. Ligaments connect bones to other bones and prevent excessive move- ment and dislocation. The iliofemoral, pubofemoral and ischiofemoral ligaments and the ligamentum teres all help stabilize the hip joint. These ligaments supply the most support anteriorly during hip extension and the least during hip flexion. As a result, most hip dislocations occur because of a proximally directed force with the hip in 90 degrees of flexion.
Joint Capsule. The capsule, which encircles the joint and femoral neck, is very strong. Its strongest aspects are the anterior and superior aspects, reinforced primarily by the two strongest ligaments, the iliofemoral and ischiofemoral ligaments (Norkin & Levangie 1992).
Positioning. The hip joint is most congruent under high loads and less so under low loads. It is most stable in quadruped (structurally) and in hip extension (owing to ligamentous tautness). Therefore, there is a greater chance of injury during adduction and flexion.
The following muscles all act at the hip joint to produce its various motions.
Extensors. Gluteus maximus, hamstrings (long head of biceps femoris, semitendinosus, semimembranosus).
Flexors. Iliopsoas (iliacus and psoas), rectus femoris, tensor fasciae latae, sartorius.
Adductors. Pectineus, adductor brevis, adductor longus, gracilis, adductor magnus.
Abductors. Gluteus medius, gluteus minimus, tensor fasciae latae.
External Rotators. Obturatorius internus and externus, gemellus superior and inferior, quadratus femoris, piriformis.
Internal Rotators. The anterior portion of the gluteus medius and the tensor fasciae latae contribute to this action, but no muscle does internal rotation as its primary function (Moore 1992).
When symptomatic, clients usually have pain with passive hip flexion and adduction. Hip bursitis can be associated with trauma or, more likely, overuse. An overuse injury is due to excessive friction on the bony surface of the greater trochanter. The greater trochanter is a large, somewhat rectangular projection from the junction of the femoral neck and the long “body” of the femur bone. It acts as an attachment point for several muscles in the gluteal region.
A bursa is a fluid-filled sac that allows smooth motion between two uneven surfaces. For example, in the hip, a bursa rests between the bony prominence over the outside of the greater trochanter and the firm tendon that passes over this bone. When the bursa sac becomes inflamed, the client may experience pain each time the tendon moves over the bone. Because a client with hip bursitis moves this tendon with each step, hip bursitis symptoms can be quite painful.
Clients can prevent bursitis symptoms through good conditioning habits involving strengthening and lengthening of all the myofascial structures. At the same time, they should avoid overuse and implement cross-training.
- Tight abductors, iliotibial band (ITB).
- Weak abductors.
The type of treatment a physical therapist or athletic trainer implements for this diagnosis will depend on the cause of the bursitis.
ITB Flexibility. This hip abductor stretch will improve flexibility:
- Begin lying supine and loop towel or yoga strap around bottom of foot. Pull one leg across body with knee unbent, maintaining neutral rotation of base leg.
- Hold 30 seconds; 3 reps each side.
1. Standing pulley hip abduction.
- Begin by standing parallel to low pulley and fasten ankle loop around outside leg (leg farther from pulley).
- Place inside hand (hand closer to pulley) on pulley arm support. Remain standing upright with slight bend in both knees and abduct outside leg against resistance of pulley.
- Slowly and with control bring outside leg back to starting position, and repeat.
- Perform 12–15 reps, 3 sets each side.
2. Quadruped hip external rotation.
- Begin in quadruped with neutral spine. Bring either knee out and away from body until thigh is parallel to mat. Hold 7 seconds, and then lower knee to starting position. Perform 12–15 reps, 3 sets each side.
Rules of Thumb:
- All exercises should be pain free.
- If pain returns in hip or gluteals, refer client back to physician or treating healthcare professional.Total Hip Replacement (THR)
Perhaps because of the aging population, more clients with a history of THR are active in health clubs these days. Such individuals must take precautions to avoid specific motions. When training a client with THR, try to be aware of the incision location, as this will dictate the precautions that are needed. Often, clients are restricted from doing the movements of hip adduction (leg crossing), external rotation (breast stroke) and hip flexion greater than 90 degrees (excessive passive hip flexion stretch). However, I have also seen clients who must avoid hip extension because of their specific surgery technique. It is paramount that you communicate with your client’s physician or physical therapist so that you are informed about the specific needs.
The most common reason for hip replacement surgery is the wearing down of the hip joint from osteoarthritis. Rheumatoid arthritis (a chronic inflammatory disease that causes joint pain, stiffness and swelling); avascular necrosis (loss of bone caused by insufficient blood supply, commonly due to femoral neck fracture or disease); injury; and bone tumors may also lead to breakdown of the hip joint and the need for hip replacement surgery. (See the website www.niams.nih.gov/hi/topics/hip/ hiprepqa.htm#2 for more information.)
Clients may demonstrate a weakened lower extremity before the surgery, as pain may have been limiting their activities. Postsurgery, they will require generalized strengthening of the legs, cardiovascular conditioning and balance training in accordance with their specific precautions.
Post-THR individuals will have physical therapy in a hospital setting, usually followed by a bout of outpatient therapy. They will likely be able to perform hip Thera-Band® exercises, partial squats and isotonics in all appropriate hip motions before coming to you for their postrehabilitation programming (Brotzman et al. 1996).
Flexibility. Include exercises to improve flexibility in these areas:
- Quadriceps (prone).
- Hamstrings (no greater than 90 degrees of hip flexion).
- Gastrocsoleus complex.
Strengthening. An effective strengthening exercise is Thera-Band loop walking. Place a Thera-Band loop above the ankles and perform the following movements:
- Resisted lateral walking.
- Alternating mini side squats: 30–60 seconds each, 2–4 reps.
- Step-ups: 10–12 reps, 3 sets.
- Prone hip extensions: 10–15 reps each side, 3 sets.
- Knee extensions: 12–15 reps unilaterally, 3 sets.
- Recumbent bike: 5–30 minutes, as tolerated.
- Walking: 5–30 minutes, as tolerated.
- Swimming is indicated, but certain strokes need to be avoided depending on incision location. Check with client’s physician for specific precautions. Alternatively, client can perform water walking for 5–15 minutes, as tolerated.
- Standing hip abduction (with and without upper-extremity support); 10–12 reps, 3 sets.
- Single-leg stance: hold 15–30 seconds (or max), 3 reps.
Rules of Thumb:
- Always analyze new additions to the routine for compliance with precautions.
- Be aware that seated exercises should not be done in a deep chair or machine, as these may increase hip flexion to more than 90 degrees.
Adductor strains are common among ice hockey and soccer players. The terms pulled groin and groin strain are describing a strain, overstretching or some tearing away of the muscles of the medial thigh. The damage commonly involves the iliopsoas and/or the adductor group of muscles. The injury usually occurs in sports that require quick starts (hockey, soccer, football).
- Tight adductors, iliopsoas.
- Weak gluteus medius and minimus, weak lower abdominals.
Clients should come to you for postrehabilitation after progressing through strengthening isometrics and after using modalities designed to decrease pain. A physician or physical therapist should have cleared the clients for more advanced strength training techniques.
1. Butterfly stretch with anterior pelvic tilt, seated against wall (adductors, iliopsoas).
- Begin in seated butterfly stretch position, anteriorly tilt pelvis and actively contract abductors to bring knees toward floor.
- Hold for 30 seconds, 3–5 reps.
2. Prone press-up (iliopsoas).
- Begin prone with palms beneath shoulders. Contract gluteals and press up through palms while maintaining pelvis contact with floor.
- Hold for 30 seconds, 3–5 reps.
Source of flexibility exercises: Kibler, Herring & Press 1998.
1. Hip hitching (gluteus medius and minimus).
- Stand on one leg on small step, then bend unsupported leg slightly, so pelvis can move up and down—but do not lift leg up. Unsupported hip and leg need to move up and down as unit, to provide suitable load for hip abductors to pull up. Ensure lumbar spine is in neutral position. Allow hip of unsupported leg to drop down slightly. Whole leg should lower with hip as it drops a small amount, keeping pelvis square at front.
- Using standing-leg gluteals only, pull free-leg hip back up to level position. As hip lifts up, weight of leg comes back up with it, working hip abductor muscles.
- Perform 15 reps, 3 sets each side.
2. Double-leg lowering (lower abdominals).
- Begin on floor with hands behind head and legs extended up to 90 degrees of hip flexion. Lift head off mat and keep it lifted throughout exercise. Inhale and lower both legs 5–10 inches, then exhale and raise both legs back up to starting position.
- Perform 15 reps, 3–5 sets.
Agility. Use agility training to increase dynamic stability of the lower extremities.
1. Perform specific skills related to client’s sport/activity.
2. Conservatively ramp up “quick start” training with sprints, cutting and change-of-direction drills.
Rules of Thumb:
- Avoid sudden increases in training program intensity.
- Continue to stretch the adductors and iliopsoas daily throughout progression and maintenance phases of the program.
Trochanteric Bursitis. To avoid compressive forces, steer clear of exercises requiring the client to lie on the injured side.
Total Hip Replacement. Remember to review the exercise program frequently to ensure you are consistent with the postoperative precautions the physician has given your client.
Adductor Muscle Strain. Stretch the client’s adductors and iliopsoas throughout the program, especially when working on agility.