Thigh
and Hamstring Injuries
Lisa M. Bartoli. DO, MS, FAAPMR
Thigh injuries are extremely
common in sports, occurring in the hamstrings and quadriceps muscle groups. Any sports activity requiring explosive bursts
of speed or quick changes in direction might cause injury to these muscle groups. Early and complete rehabilitation makes
for a faster return to play and reduces recurrence of these injuries.
HAMSTRING AVULSION
Common Causes
An avulsion
is a tearing away. Avulsion injuries are less common than strains of the musculotendinous junction and often occur when the
hip is forced into flexion while the knee maintains full extension, as happens in water skiing. Commonly the entire tendon
is avulsed from the ischium. Adolescents tend to have a higher incidence of bony avulsion injuries in general.
Identification
Athletes with avulsion injuries have significant functional deficits, including a loss of
speed, power, and agility as well as a poor return to prior functional level. They will have persistent pain, pain with sitting,
weakness in full flexion, and poor leg control, especially when descending stairs or walking downhill. Sciatic nerve injury
is also a possibility. X-rays can usually identify a bony avulsion injury. MRI can identify the avulsion as well as the extent
of tendon disruption or tearing.
Treatment
Treatment for acute avulsions follows the PRICE protocol (protect,
rest, ice, compression, and elevation) common for all acute injuries. If the displacement of the hamstring tendon from the
ischium is greater than 2.5 centimeters (1 inch), or if conservative treatment has failed, the athlete will almost certainly
require surgery. The current trend is to surgically repair acute avulsion injuries even when displacement is less than 2.5
centimeters. The earlier surgery occurs, the argument goes, the sooner the athlete can return to sport. For many athletes,
early surgery is preferable to prolonged conservative treatment that might lead to additional weeks of downtime.
Return to Action
Return to play follows the same criteria as described for hamstring strains. Surgical repair
calls for a prolonged rehab under the supervision of a physical therapist. The surgeon must clear the athlete before he or
she returns to sport.
HAMSTRING STRAIN
Common
Causes
A strain is a degree of tearing of the muscle fiber. The tearing or straining of
hamstring muscles, particularly the long head of the biceps femoris, occurs frequently in athletics, particularly in
sports that require brisk accelerations of speed and cutting, such as rugby, American football, soccer, and tennis. Although
complete tears can occur, most tears are partial and occur at the myotendinous junction as a result of a failed lengthening
of the muscle (eccentric contracture).
The hamstring muscle group includes three distinct muscles:
the biceps femoris, the semitendinosus, and the semimembranosus. This group crosses two joints: the hip and the knee. Injuries
to the hamstrings generally occur at the musculotendinous junction. Of the three muscles in the hamstring group, the
biceps femoris is most likely to be injured. Factors that predispose an athlete to hamstring strains include insufficient
warm-up, fatigue (strains tend to occur later in training or competition and later in the competitive season), poor muscular
coordination, excessive pelvic tilt, prior hamstring injury, and imbalance in muscle strength between the hamstring and
quadriceps (in which the hamstring is weaker).
Poor flexibility of the hip flexors and quadriceps
alters the lumbopelvic mechanics by causing the pelvis to tilt anteriorly and increases the degree of lumbar lordosis (the
curve in the low part of the back), which places extra tension on the hamstrings. Poor running mechanics in which the athlete
has excess forward lean causes the gluteus maximus, the prime hip extensor in sprinting, to function poorly. This results
in overstriding, increasing the hamstring length and making strain more likely.
Hamstring tendinopathy,
a related injury, is an overuse injury resulting in dense fibrosis (thickening of muscle fibers) and occasionally, hyaline
degeneration at the attachment of the hamstring to the ischium. It differs from tendinitis in that tendinopathy represents
more of a chronic injury whereby the actual muscle fibers begin to degenerate and undergo structural changes. In tendinitis,
the muscle fibers are intact but there is local inflammation due to acute injury. This injury is commonly seen in middle-
and long-distance runners.
Treatment
Approach treatment of
hamstring strains and hamstring tendinopathy in phases. In the first phase, the goal is to decrease the amount of local bleeding,
swelling, pain, and inflammation. Nonsteroid anti-inflammatory (NSAID) medications can help limit inflammation and allow earlier
rehab, but these should be used for only three to seven days post injury because they can delay muscle regeneration and interfere
with healing.
During the first phase of treatment, acute conservative care of hamstring strains follows
the guidelines for most soft-tissue injuries. Start icing and light compression with an ace wrap as soon as possible. The
injured hamstring should be protected by limiting movement on hills, ramps, stairs, and uneven surfaces. The use of a
cane or crutches should help reduce weight bearing, but holding the leg flexed at the knee and off the ground with crutches
can aggravate the injury. A flat-foot gait with assistive devices is advocated until the athlete is walking pain free. If
formal rehabilitative therapies are available, the use of concurrent electrical stimulation and ice might speed healing.
About seven or eight days after injury, the second phase begins. Most experts agree that electric stimulation,
passive range of motion, myofascial release, and isometric exercises can be introduced at this point. The athlete should work
on varying the position of the hip and knee during contraction. Stretching the hamstring while maintaining an anterior pelvic
tilt, and holding each stretch for 20 seconds, has also been shown to be helpful. Pulsed ultrasound therapeutic massage might
further reduce swelling and promote rehabilitation. Once the athlete has regained voluntary control of the muscle, he or she
may begin gentle stretching.
Once the athlete has achieved 75 to 80 percent of normal range of motion,
he or she begins resisted stretching techniques, such as isometric contract-relax exercises, active isolated stretching, and
proprioceptive neuromuscular facilitation (PNF). Initial strengthening through concentric resistive exercises (shortening
contractures of the muscle), either isokinetic (constant speed) or isotonic (constant weight), are preferred over eccentric
resistive (lengthening contractures of the muscle) exercises because they pose less risk for reinjury. Swimming and cycling
on a stationary bicycle may be added at this time if pain allows. All exercises should be performed within pain-free range
of motion.
The third phase is the remodeling phase and occurs anywhere from one to six weeks after
the initial injury. Pain-free static stretching of the hamstring, psoas, and quadriceps continues to be important to the rehab
program. Eccentric strengthening, isokinetic strengthening, and proprioceptive neuromuscular facilitation is also introduced.
Some of the stretching and strengthening exercises should include hip rotation. This is important because many sport movements
such as pivoting, cutting, or changing direction involve hip rotation, both internal and external, with hip extension,
which places stress on the hamstring.
In the final phase of treatment the goal is returning the athlete
to sport. This phase includes sport-specific activities, emphasizing increasing hamstring strength and flexibility to
preinjury levels or better. The athlete progresses from jogging to sprinting; he or she performs cutting and pivoting activities
as well as drills that incorporate rapid acceleration and deceleration.
Other modes of treatment that are beneficial
for hamstring strains include ultrasound (late in the treatment), deep friction massage, and neuromobilization. Acupuncture
is also helpful and may be used as soon as the injury occurs and throughout the rehab program.
For
athletes with complete proximal hamstring tendon tears who have persistent strength deficits despite conservative treatment,
surgical repair and subsequent rehab have been shown to restore near complete strength and promote a return to athletic activities.
Return to Action
For hamstring strain and tendinopathy, the athlete is
cleared to return to play when he or she can participate in sport-specific activities pain free. Some professionals advocate
return when isokinetic testing reveals strength within 10 percent of the sound leg at slow and fast speeds with equal flexibility
and endurance. To prevent recurrence of the injury, the athlete should continue regular stretching and strengthening and should
always warm up properly. Faithful compliance with hamstring and other hip girdle musculature stretching and continued balanced
strengthening of the quadriceps and hamstrings will help prevent reinjury.
One of the greatest risks
for hamstring strain is prior hamstring strain, so complete and continued rehabilitation is necessary. Recovery can occur
as quickly as one week or take six weeks or more, depending on the grade of the strain.
FEMORAL STRESS FRACTURE
Common Causes
Fractures of the neck of the femur occur in only 1 to 10 percent of all lower-extremity stress
fractures, and femoral shaft stress fractures are even less common. Stress fracture can occur anywhere in the medial femoral
shaft but happens most commonly at the junction of the proximal and middle third. The femur is bowed anteriolaterally at this
junction; it is also the site of origin of the vastus medialis and the insertion point for the adductor muscle group.
The cause of femoral neck stress fractures might be unclear, but biomechanics, hormonal influences, and
alterations in bone mineral content likely playa part. Typically, athletes involved in endurance sports such as running and
soccer experience such injury. Risk factors for the development of femoral neck and shaft stress fractures include increases
in mileage, intensity, or frequency of running. A new running surface or new shoes might also be implicated, as might low
bone mineral density, and in those with a short and thin femoral shaft, poor alignment, leg-length differences, weak lower-extremity
muscles, and in those who are overweight, and, in females, amenorrheic (Brunet and Hontas 1994; Provencher, Baldwin, Gorman,
Gould, and Shin 2004). Coxa vara (hip deformity) is a likely risk factor for development of femoral neck stress fractures.
Identification
Because of the high rate of complications with femoral neck
fractures (avascular necrosis, fracture displacement, malunion, and nonunion), the earlier the diagnosis, the better. Athletes
with femoral neck stress fractures generally experience pain in the groin or hip. Athletes with femoral shaft stress fractures
might experience thigh or knee pain, which decreases with rest and increases with activity.
Physical
exam findings for femoral fractures are often limited. Tenderness might be noted in the area but is usually limited because
of overlying muscle. Femoral shaft fractures can be diagnosed using various clinical tests (fulcrum test, fist test, or single-leg
hop test) but imaging is the best. Femoral neck fractures might cause pain or limited movement with hopping, hip internal
rotation and flexion, and resisted hip extension.
X-rays may not reveal a fracture line early on;
the fracture site may not be visible in plain X-ray until the repair process begins (2 to 12 weeks after initial pain)
and callus formation occurs. At this time a lucent fracture line might be revealed. Radionucleotide bone scan, which can immediately
reveal a fracture, has long been considered the gold standard for early detection of stress fractures.
Treatment
Fractures to the neck of the femur occurring on the compression or medial side are considered more stable and can
be managed conservatively. Athletes usually use crutches to avoid weight bearing on the limb. X-rays can then help monitor
healing. Tension-side (outer-lateral) femoral neck fractures have a high rate of displacement, and internal fixation is recommended.
Surgical fixation often requires placing pins through the fracture site to stabilize the fragments. For some nondisplaced
tension side stress fractures, strict bed rest and weekly X-rays have good results. Athletes with stress fractures that are
not well aligned should be referred to an orthopedic surgeon for emergent reduction and fixation.
With a femoral shaft
stress fractures on the inner (medial) side, the athlete uses crutches and is allowed only toe-touch weight bearing for one
to four weeks based on demonstration of healing (through X-ray) and no pain in walking. For fractures on the outer lateral
(tension) side, if surgery was not done, no weight bearing is allowed for a minimum of six to eight weeks.
Return to Action
Return to running generally occurs 8 to 16 weeks after the onset of pain. Monthly X-rays
for three months are recommended to ensure healing and nondisplacement. Before the athlete resumes training, the cause of
the stress fracture should be determined. Amenorrheic females should undergo bone density testing and treatment for the amenorrhea
before returning to sport. Training errors should be corrected and caution taken against a rapid increase in training mileage
and intensity. Before athletes resume running they should be pain free during a fairly intense activity, such as cycling,
swimming, or pool running.
Athletes should restrict themselves to three to five miles for weeks one
to three. If they remain pain free, they can increase distance gradually back to half their normal distance over the next
two weeks. If symptoms return, the athlete should stop and return to the previous activity that did not cause pain (e.g.,
if running caused pain, the athlete returns to biking or swimming).
QUADRICEPS CONTUSIONS
Common Causes
Quadriceps
contusions result from blunt trauma (usually from a knee or thigh) to the thigh. Initially, symptoms might seem minor, but
significant swelling and pain and decreased range of motion can occur over the next 24 hours. The blunt trauma generally results
in damage to the muscular layer adjacent to the bone, thereby injuring deeper muscle than is normally involved in strains.
This injury is common in American football, rugby, karate, judo, soccer, hockey, and lacrosse.
Identification
Contusions are generally classified as mild, moderate, or severe; most are mild to moderate.
This classification is made 24 to 48 hours post injury, when swelling and hematoma have stabilized. Classification is based
on knee range of motion and physical findings. Mild contusions of the quadriceps have greater than 90 degrees of knee flexion
and mild tenderness. Moderate contusions of the quadriceps have 45 to 90 degrees of knee flexion and enlarged, tender thighs.
Severe contusions have less than 45 degrees of knee flexion and significant swelling and pain with quadriceps contraction.
If there is less than 45 degrees of knee flexion, along with severe pain and swelling, the contusion is considered severe,
and compartment pressure testing should be considered to rule out compartment syndrome.
Initial X-rays
can rule out a fracture. At two to four weeks post injury, X-rays can also rule out traumatic myositis ossificans. MRI should
reveal the specific injury as well as the size and exact location.
Treatment
Early
and aggressive treatment is the key for quick return to play and minimal complications. Athletes can return only when knee
flexion is at 120 degrees. Thus, the key is to treat the athlete early, when he or she still has 120
degrees of knee flexion. At that point, the knee is passively flexed and wrapped to maintain 120 degrees of flexion. The athlete
is braced or wrapped in this position for 24 hours and uses crutches (Aronen and Chronister 1992). Placing the quadriceps
under tension should slow the intramuscular bleeding and maximize the quad stretch.
After 24 hours,
the brace or wrap is removed; icing, electric stimulation, and passive pain-free quad stretching follow. The athlete is encouraged
to perform this passive stretch frequently throughout the day. Athletes use the crutches until they can perform a pain-free
isometric quad contraction and until swelling has diminished and the thigh has returned to normal size (Aronen and Chronister
1992). Strengthening begins with flexion and proceeds to extension. Progress exercises as motion and strength return.
If the athlete is not treated until after swelling and muscle spasm have occurred (thus making it
difficult or extremely painful to attain 120 degrees of knee flexion), a modified approach to treatment is attempted. The
prone athlete performs pain-free isometric knee-extension exercises until the quad fatigues, causing the spasms to decrease.
Once fatigue sets in, begin passive pain-free stretching of the quad. This pain-free extension, relaxation, and stretching
exercise is initially performed three times. The knee is then immobilized in a hinged knee brace at the maximum degree of
pain-free flexion. Ice and electric stimulation are added at the next treatment, and the procedure is repeated. The athlete
wears the brace continuously until he or she has 120 degrees of full-knee flexion (Aronen and Chronister 1992).
Return to Action
Athletes can return to action once they attain full range of motion, and strength is equal
to the non injured leg. Return time is often within one week for mild to moderate contusions. The athlete is fitted with a
protective pad, which should be worn for the remainder of the season. Failure to treat a thigh contusion aggressively can
delay return time up to four weeks.
QUADRICEPS STRAIN
Common Causes
The quadriceps consists of the four muscles located on the
anterior thigh: the vastus medialis, vastus lateralis, vastus intermedius, and rectus femoris. Only the rectus femoris crosses
two joints (the hip and knee) and functions as both a hip flexor and knee extensor. The other three muscles are responsible
for knee extension only.
Quadriceps strains are common in American football, rugby, soccer, track,
basketball, hockey, and other sports that require repetitive sprinting, kicking, and jumping. Strains generally occur
with a forceful (near maximal) contraction or forceful stretching of the quadriceps. Quadriceps strains generally occur at
the musculotendinous junction and can be partial or complete. Grade I strains involve minor muscle fiber disruption. Grade
II strains involve more extensive tearing of the muscle fiber with accompanying hemorrhage, and grade III strains are full
tears of the musculotendinous junction. The rectus femoris muscle is most often strained, followed by the vastus intermediate
and vastus lateralis.
Identification
If the athlete experiences more pain with knee flexion when
the hip is extended than with the hip flexed, the rectus femoris is involved. Feeling the muscle can help localize the injury
site. Defects, or a mass that occurs with knee extension, are more commonly seen with grade II and III strains. It is difficult
to palpate a defect in the muscle once swelling or hematoma formation has occurred. MRI is considered the standard for imaging
muscle strain injuries. In most cases, MRI can identify the exact location and severity of the strain.
Treatment
Treatment for quadriceps strains is similar to treatment for hamstring strains and follows a similar phase-based
approach. Once the athlete's treatment has progressed to pain-free motion, he or she begins isometric exercises at full extension
and progresses to 90 degrees of knee flexion. Straight-leg raising exercises should be avoided early on because these place
the greatest stress on the rectus femoris. Gentle and cautious active stretching is initiated in this phase. Stretching generally
starts with the athlete in a prone position, actively flexing the knee against gravity as tolerated. During the final stage
of rehabilitation, force absorption and production exercises are added-for example, jumping down from a one-foot box, absorbing
the force, and then jumping back up from that position.
Acupuncture is also helpful in decreasing
pain and swelling, which in turn promotes increased range of motion and gets the athlete through rehab faster. Acupuncture
should be used as early as possible and continued through the rehab process.
Return to Action
The athlete returns to sport when range of motion is full and pain free, when isokinetic strength testing is within
10 percent of the uninjured leg, and when the athlete can complete agility testing and sprinting without difficulty. The athlete
should continue using compression sleeves with protective padding throughout the season. Return to full activity generally
occurs two to three weeks after injury.
MYOSITIS OSSIFICANS
Common
Causes
Myositis ossificans---the formation of heterotopic (misplaced) bone in a surrounding
muscle---is a complication that often occurs with grade II and III quadriceps contusions, most commonly adjacent to the femur.
In a study of military recruits with thigh contusions, myositis ossificans developed in 20 percent of treated contusions
(Brunet and Hontas 1994).
Identification
A firm mass developing three to four weeks post contusion
might be myositis ossificans. X-rays should confirm diagnosis. It appears as a whitish collection on X-ray. This mass might
or might not be connected to the femur. Generally, it takes three to six months to mature (cease forming). Ultrasound can
detect the formation of myositis ossificans before it appears on X-ray.
Treatment
Treatment is essentially the same as for contusions. If left untreated, persistent loss of range of motion, painful
bony mass, and significant limitations in athletic function can result. Ultrasound may help to break up the myositic collection.
Additional treatments to consider are single low-dose radiation and the use of NSAIDs (specifically
Indocin or Naprosyn) for two to six weeks (Larson, Almekinders, Karas, and Garrett 2002; Wang, Lomasney, Demos, and Hopkinson
1999). Both are advocated to inhibit the formation of further heterotopic bone. Radiation may help in heterotopic bone breakdown.
In rare instances, surgical excision is needed. If so, it is imperative that the bone formation reach
full maturity, which takes about six months, before being surgically excised. If the formation is cut out before it reaches
maturity, it might return even greater than its original size. If surgery is done, the athlete may be advised to begin a postoperative
course of radiation to inhibit the re-accumulation of heterotopic bone.
Return to Action
Myositis ossificans can delay return time beyond what is required for a contusion. A physician or physical therapist
should make the call.
COMPARTMENT SYNDROME
Common Causes
In this condition, the "compartment" refers to
the fascia or covering of the quadriceps muscle group that encircles the muscle. Compartment syndrome occurs in contact sports
when a knee, helmet, or other hard object forcefully contacts the quadriceps or anterior muscle group. Rarely, excessive bleeding
and edema following a quadriceps contusion can result in compartment syndrome. When the swelling in the anterior compartment
increases, compartmental pressure rises. This fascia does not have the ability to expand a great deal. Thus, a large amount
of swelling causes an increase in pressure, which ultimately deprives the muscle of an adequate blood supply, effectively
starving the muscle of oxygen and nutrients. If this process is allowed to continue, it can result in muscle death.
Identification
Clinically, pain out of proportion to the injury, pain at rest, pain with passive knee flexion,
and a diffusely tender and tense thigh suggest the possibility of compartment syndrome. Sensory deficits might occur along
the saphenous nerve (medial knee and tibia). Motor deficits and absent pulses are late findings that imply more severe and
permanent muscle damage.
Diagnosis is made by obtaining compartment pressures from the anterior thigh compartment. The
critical pressure duration that can lead to permanent damage ranges from four to eight hours.
Treatment
The treatment for acute thigh compression is fasciotomy, or surgically cutting the fascia to allow the muscle to
receive an adequate blood supply. The fascia is surgically closed again once the swelling resolves. Following surgical
decompression, early rehab is begun to limit swelling, pain, and atrophy as well as to improve range of motion.
Return
to Action
Following a complete rehab program, most athletes can return to their sports within
8 to 16 weeks, once they are cleared by their physician.
FROM: SPORTS INJURIES GUIDEBOOK
By Robert S. Gotliv, DO Editor--Chapter 12
