BioMechanics
May 1999

Sports Medicine:
Athletic hip injuries warrant attention

By Barbara Sanders, PhD, PT, SCS

Although sports injuries to the knee, ankle, and shoulder are well documented and discussed, little attention has been devoted to injuries of the hip and thigh. This is due to the relatively low incidence of problems in these specific anatomic areas and the infrequency of associated career-threatening injuries. However, several hip and thigh injuries have potentially dire consequences with respect to function and return to normal athletic activity if managed improperly.

In the past 20 years, our knowledge of sports injury, its pathogenesis, and its appropriate treatment has increased dramatically thanks to increased athletic activity in our population. The incidence and distribution of injury to the hip and thigh vary significantly depending on the sporting activity being considered. Contact sports like football, rugby, and soccer have a relatively high incidence of such injuries as hip pointer, hematoma, and traumatic dislocations and fractures of the hip. In the endurance-type sports, such as running and swimming, the overall incidence of traumatic injury is much lower and tends to be in the stress or overuse category. Serious injuries result from both types of activities.

Sophisticated imaging techniques like computed tomography (CT) and magnetic resonance imaging (MRI) have allowed medical specialists to better understand sports-injury patterns anatomically and pathophysiologically. Additionally, significant progress has been made in rehabilitation concepts and techniques. Where conventional wisdom once called for immobilization in casts, the standard of care is now early mobilization following injury.

Stress fractures

The incidence of femoral stress fracture in the entire lower extremity is less than 2%.^1,2 The exact cause of femoral stress fracture is unknown, but is definitely related to overuse, as evidenced by its frequent occurrence in long-distance runners. The incidence of these injuries is higher in women than men, although the exact reason is unknown. The patient with a femoral-neck stress fracture complains of pain in the groin or thigh that increases with activity. It may occur during running activity and persist for hours afterward. Rest, however, generally brings relief.^1,2

These individuals almost always experience onset of pain some three to four weeks after increasing a training program, participating in strenuous competitive events, or altering their training regimen or equipment. The initial treatment involves absolute rest and cessation of running. Stress fractures are classified as tension or compression fractures as determined by x-ray. Tension fractures may require surgery and do not have a good prognosis. Compression fractures are treated conservatively and should resolve. Return to athletic activity for these individuals should be allowed only after fracture healing and remodeling is complete, which can take up to 12 months.

Fractures

Even though these injuries are extremely rare, they are important because of possible complications. The incidence of avascular necrosis is much higher in young athletes due to the precarious nature of the blood supply to the subchondral region of the femoral head.¹ The recommended treatment for these fractures involves open reduction and internal fixation (ORIF). After surgery, most authors recommend immobilization in a brace or hip spica. Intertrochanteric hip fractures, which vary in degree of fragmentation and displacement, are treated surgically with ORIF as well. These require a moderate amount of time for healing (six to 12 weeks), and the complications associated with this fracture are minimal, if anatomic reduction is accomplished and maintained.

Traumatic fractures to the femur are rarely seen in competitive athletics, but can occur. Another type of fracture that occurs is avulsion of the lesser trochanter at the attachment of the iliopsoas tendon to the proximal femur. This results from forced hip flexion over an extended extremity. A commonly seen example occurs in soccer when a player tries to kick a ball but finds the resistance of another foot or the ground in the way. These injuries are initially painful, but usually heal over a period of four to six weeks. They are treated conservatively and surgery is not indicated.

Muscle strains

O’Donoghue has described the spectrum of muscle injury quite well.¹⁰ He classifies muscle strain injuries into one of three categories, depending on the amount of damage. In first-degree strains, there is little tissue disruption, but there is a low-grade inflammatory response to the injury. There is no loss of strength or range of motion. In second-degree strains, there is actual tissue damage with disruption of some fibers. Strength and range of motion are compromised and may result in any degree of involvement up to total loss of strength and function. The most severe category of injury, a third-degree strain, indicates a complete disruption of the musculotendinous unit (rupture) with grossly visible damage and complete loss of function to the unit.¹⁰

The initial treatment of acute muscle strain injuries has typically involved RICE: rest, ice, compression, and elevation. Progressive treatment includes stretching to improve range of motion, reciprocal strengthening exercises, support bandaging, and medication. Medications usually include analgesics, nonsteroidal anti-inflammatory drugs, and occasionally steroids. Surgical intervention is rare, even with complete ruptures of the musculotendinous unit, as these ruptures are difficult to repair due to the nature of the muscle tissue itself. Treatment protocols are empirical as there are few outcome studies addressing the effects of different treatments.

Prevention is a key element in managing muscle strain injuries. A number of factors have been cited in the literature as relevant to the prevention of muscle injury. These include muscle strength, fatigue, warm-up muscle temperature, passive stretching, previous injury, and the biomechanics of an activity.¹¹

Adductor strains (“pulled groin”) are frequently seen in ice hockey, soccer, high jumping, water skiing, swimming, and football—all activities requiring quick direction changes or propulsion. These injuries occur at the muscle-tendon junction; the adductor longus is the muscle most frequently involved.

Hamstring muscle injuries are caused by either a vigorous stretch or a rapid contraction of the muscle. This muscle group is the most frequently strained muscle in the body.^11,12 The injury is commonly seen in activities involving running or sprinting, such as soccer, football, and rugby. Recurrence is common with hamstring injuries.

Quadriceps strains are not common in sports. When seen, they are most frequent in soccer, weight lifting, football, rugby, and sprinting, and usually involve the rectus femoris. This type of injury can be very disabling to the athlete because the quadriceps muscles are powerful extensors of the knee and work with the glutei and hamstrings for normal coordinated walking, running, and jumping.

In first-degree strains, immediate treatment includes rest, ice, compression, and immobilization. As symptoms subside, these modalities are followed by stretching and strengthening and pain-free return to activity. Minor strains should not be treated lightly, as many recurrent or severe injuries are preceded by minor ones. Analgesics or NSAIDs may be given as necessary. The athlete should ambulate with full weight-bearing only if gait is normal and pain-free; if not, ambulation should occur with crutches. Second-degree injuries should be handled similarly to first-degree injuries except for a longer treatment period. The exact length of the treatment period depends on the extent of the second-degree injury, since there is much variation.

Controversy exists concerning treatment of third-degree injuries. Immobilization in extension is indicated for 48 hours. In addition, some physicians¹³ have advocated the use of steroid injections into the site of the strain, although the benefit of this procedure has not been well documented.

Exercises should include pain-free stretching and isometric contractions. Intensity should be gradually increased, keeping activities pain-free. Using this guideline will prevent further injury due to over-aggressive rehabilitation. Once the athlete has achieved full pain-free range of motion and there is no residual soreness or tenderness, additional strengthening exercises can be included—closed kinetic chain, isokinetic, and isotonic exercises. Therapeutic ultrasound and gentle friction massage may be indicated for the resolution of adhesions within the muscle.

The rehabilitation program should gradually build to include sport-specific activities, such as running, cutting, and jumping drills. The athlete should be cleared for return to participation or competition when strength, endurance, flexibility, coordination, and athletic agility required for that sport are judged by the rehabilitation team to be acceptable.

Contusion

“Hip pointer” is a nonspecific term that generally refers to an injury to the iliac crest as the result of a blow. A hip pointer is usually a contusion of the iliac crest over the tensor fasciae latae muscle belly with associated hematoma.

Contusions of the anterior thigh and the quadriceps muscle groups are quite common. Injuries of this nature are most often seen in sports such as football, rugby, soccer, basketball, and hockey. Contusions of the quadriceps are often accompanied by muscle strain injuries of that same muscle.

Treatment for the first 24 to 48 hours should follow the RICE protocol. Loss of range of motion may be the best indicator of the severity of the injury. Further treatment following the immediate acute care should continue to provide compression and cooling to the entire area to minimize bleeding. Reevaluation may indicate continued flexion, compression, and icing for another 12 to 24 hours. Continued swelling, despite this regimen, may indicate hemorrhage and a need for further medical evaluation. The athlete should be put on crutches if he or she is unable to accomplish a pain-free gait; weight-bearing status should be nonweight-bearing for 48 hours, then partial weight-bearing in pain-free range.

Stretching

The three common techniques include static stretching, ballistic stretching, and proprioceptive neuromuscular facilitation (PNF) techniques. Static stretching is the classic stationary stretch in which the limb is moved to position and stretched to a point of mild discomfort. Ballistic stretching consists of moving the limb to position and adding quick bobbing movements at the end of the range, instead of the long, slow stretch used in the static technique. Ballistic stretching uses available range of motion and limb weight or muscle contraction to accomplish the increased flexibility. While somewhat controversial, it is valuable for the development of dynamic flexibility. PNF techniques are used to place specific demands on the muscle; i.e., promoting or hastening the response of tissues through stimulation of the proprioceptors.

There is no consensus on the best stretching technique.^17-19 Regardless of the techniques selected, it is widely accepted that stretching for 15 seconds may be as effective as stretching for two minutes and that individual responses to flexibility programs vary considerably.^18-20 For increased flexibility to be maintained, it must be gained over a period of time greater than six weeks. To maintain flexibility, stretching should be done at least once a week. To gain flexibility, a program should be incorporated into the exercise routine three to five times per week. Zachazewski¹⁷ suggests the following flexibility routine: general warm-up, preparticipation stretching, neuromuscular warm-up, participation, and postparticipation stretching.

Injuries to the hip structures are less frequent than to other parts of the leg but have potentially serious, career-threatening consequences. Diagnosis is often problematic due to the prevalence of many confusing medical processes that can mimic these disorders. An accurate medical history is imperative for reaching a specific diagnosis. Open-mindedness is also important to prevent inaccurate “shotgun” diagnoses, which can lead to improper management of for these conditions.

Barbara Sanders, PhD, PT, SCS, is chair of the department of physical therapy at Southwest Texas State University in San Marcos.

Management Of Hip Disorders