Personal you.

Straighten your knees." "Pull up your kneecaps." Familiar corrections?

Not uncommon to dancers of all ages is a kneecap slip (subluxation), the trick" kneecap.

According to William A. Liebler, M.D., pioneer dance doctor, kneecap problems should never be overlooked. Here he explains the patella's function, describes the causes of pain and dysfunction, and advises exercises to strengthen the kneecap's surrounding muscles.

Patella: a flat, triangular, movable bone on the front of the knee; the kneecap. (See X-ray.) The kneecap navigates the best course during a movement by tracking up and down in its groove. The cartilage covering the back of the kneecap has approximately seven articular surfaces that each come into play at different degrees of motion. This faceted undersurface is important to its stability. When the knee is bent or straightened the patella absorbs the tremendous pressure on one and then another of its facets. It is a highly synchronized and sophisticated progression. The tiniest deviation from that blueprint can cause trouble. "The knee is a peculiar mechanism," says Liebler, "complex, and vital to the function of dance. Knee pain may come from a number of sources, such as the patella, injury to the supporting ligaments, injury to the shock absorbing internal cartilages (menisci), the cartilage lining attached to the bone, or injury to the bone itself. Only medical examination can determine the exact area and true cause through an X-ray, bone scan, or joint aspiration if there is swelling, and an MRI to determine underlying patellofemoral damage. Treatment for damage can be remedied by medication, physical therapy, or surgery, but neglect can reach a stage where it may end a dancer's career."

Patella Tendonitis 

Inflammation due to strain at the junction between the bone of the patella and the tendon commonly occurs when there is an imbalance of the quadriceps (the long, four-part thigh muscle), such as weakness in the medial (middle) area with a stronger lateral (side) muscle. When outside muscles are overused it is likely that the patella will move laterally when the quadriceps are contracted. Physiotherapy correctly carried out will avoid more drastic treatment; ignoring the condition can cause excessive compensations to take place in the lumbar spine with injuries occurring there. TEACHER ALERT: According to Liebler, when the Achilles tendons (above the heel) are tight or the feet are weak, the patella cannot absorb the shock of landing and the patellar tendon takes the strain.

A period of rapid growth in a young student may produce temporary inadequacy of the quadriceps and cause the dancer with a jarrete configuration (knock-knees or saber-shaped legs) to push back and lock the kneecaps instead of placing the weight more forward on the feet. Tightness at the front of the hip and tight hamstrings, often associated with growth, may cause patellar tendonitis by inhibiting the movement of the quadriceps causing the knee to be the main shock absorber. Repetitious kneeling, squatting, or jumping may also produce patella tendonitis. Physiotherapy is again indicated. If treatment is not effectively administered, the area may develop spurs, the pain become chronic, or develop into chondromalacia.

Patellar Chondromalacia

Softening (malacia) of the cartilage (chondro) of the kneecap is painful and can interfere with performance. A higher incidence of patellar chondromalacia exists in women, although men are also subject to the condition. Females have a wider angle from the femur (thigh bone) at the hip joint to the knee and are more commonly knock-kneed. Narrower angles are characteristic in males, who are more commonly bowlegged.

The knock-knee configuration may lead to problems with the patella and Pronation (inward rolling of the foot). Pronation may then result in injuries to the sole of the foot, the tendons around the ankles, and cause shin splints, or a twist inward that strains the inner aspect of the knee.

Liebler advises preventive measures and early detection if the following symptoms in or around the knee exist: 1. Pain in the front of the knee. 2. Clicking or grinding during a plie of more than 45 degrees or when landing in demi-plie from a jump. 3. Recurrent swelling, secondary to inflammation of the joint or synovial membrane that secretes fluid and lines the joint cavity. 4. Buckling which follows pain is a warning to take it easy on that knee. 5. Recurrent dislocation of the patella requires that the knee be put into as much hyperextension as possible and manual pressure applied to the kneecap to push it back into place. Immobilization should follow.

Patellar chondromalacia may be caused by trauma such as a single or repeated impact to the kneecap, seen especially in male dancers who do knee drops.

Patellar malalignment with dislocation of the kneecap

One or a combination of factors may cause this condition:

1. A kneecap with abnormal undersurface facets that are either too shallow or at the wrong angle, uneven medial and lateral facets, or only a lateral facet. 2. A tight lateral capsule that pulls the kneecap toward the outside of the knee. 3. An abnormal overpull of the vastus lateralis (outside) muscle portion of the quadriceps against a weak vastus medialis (middle portion). 4. A pronated foot. 5. An abnormal rotation of the femur (thigh bone) near the hip joint. 6. Knock-knees. 7. A shallow femoral groove at the kneecap.

All of these factors, or any combination, may occur in the same dancer, producing unstable kneecaps that tend to sublux or slide toward the outside, sometimes actually dislocating by coming out of the groove and locking the knee into a certain position until the patella is moved manually into the center. These factors are usually found in very loose ligamented females and in those with swaybacked knees.

Although surgical procedure to release the tight lateral capsule is frequently performed, unless the cause of the imbalance is diagnosed and fully corrected by postoperative physiotherapy the surgery may make the patient worse: over-releasing can make a dancer too weak to support body weight; under-releasing may allow recurrent dislocation of the kneecap. A lateral release and tightening of the medial capsule on a dancer with ligamentous laxity will only stretch out in time and the dancer will be right back to the original condition.

In addition to treatment, exercises should be directed toward rebalancing muscles, and rebalancing muscles, and strengthening the quadriceps and other weak muscle groups, stretching any tightness in the front of the hips, hamstrings, and calf muscles. A light brace may be worn. In the case of swaybacked knees, an orthopedic lift inside the heel of the ballet shoe may be advised for temporary use.

Patella malalignment without out dislocation of the kneecap

This condition is frequently caused by a tight lateral capsule and a weak medial capsule causing an overpull in the lateral direction. It may be congenital, may develop if there is ligamentous laxity, or occur with prolonged dancing or aging, and may lead to early degenerative arthritis. The capsule tightens, increasing the pressure on the lateral facet of the kneecap, and the surface of the kneecap is worn down. This condition may respond to anti-inflammatory medication, a brace for support, or a lateral capsular release.

True chondromalacia is persistent and can be difficult to treat if it is long established. Caught early, treatment is easier. Arthroscopic evaluation (surgery using an instrument for viewing the interior of the knee joint) may be necessary to see the amount of abnormality between the undersurface of the patella and the front of the femoral grooves or patellofemoral joint. The judicious use of a shaving instrument to smooth the rough and painful surfaces of the bones occasionally helps, but many times it can cause more problems than it solves and is not necessarily a long-term solution. Removing damaged areas of the cartilage often makes the knee more vulnerable to further tears, thus beginning a vicious cycle. A lateral release may aggravate the muscle weakness and increase the imbalance unless it is followed by a strengthening program, especilly if true tightness has been demonstrated in the lateral capsule which cannot initially be stretched.

"Correct patellar alignment is one of the most important factors among all the things that determine the physical potential of the dancer," says Liebler. "Patella problems can be seen in students seven to nine years of age or younger; they worsen, if uncorrected, in the early teens. These young dancers struggle with dislocation of the kneecap, patellar pain, and difficulty with turnout to the point of compensation and recurrent injuries. Early analysis and correction of the young student's patellar malalignment problems can improve the chances for a career."

TEACHER ALERT: In addition to your corrections concerning the direct-line relationship between the foot and the knee in plie, the three-point placement of the foot (heel, big toe, little toe) to avoid pronation, and the aligned lower spine to provide support, it is necessary to look for possible congenital problems in the kneecap. Suggest orthopedic evaluation by a specialist knowledgeable in knee problems or physiotherapeutic exercises if your corrections do not result in improvement.

Osgood Schlatter's Disease.

This condition is characterized by pain and tenderness, and a swollen, warm area indicating inflammation of the growing portion of the bone at the upper end of the tibia (shin bone) to which the patellar tendon is attached. Repeated stress can cause enlargement of the tibial tubercle--the small rounded prominence on the bone--that is secondary to healing and scar tissue. Although many doctors feel that an adolescent patient will outgrow this condition, it has been observed in people well into their 30s and 40s for whom surgery is the only cure to alleviate the condition. Surgery before growth ceases is contraindicated: Only when growth is fully finished can surgery be safely done so no possibility of deformity can result.

The condition is commonly produced by relative weakness in the quadricep muscles, and during a period of rapid growth manifests as a jerking pull on the lower tendon rather than an even, controlled pull.

The student should cease activity except for building up quadricep muscles, as well as the inside thigh muscles, gluteals (buttock muscles), and hamstrings (back thigh muscles): A long and rigorous road but well worth the travel.

When the pain subsides, the student may return to class. If strenuous activity is continued despite pain, the bony tibial tubercle may become permanently enlarged and appear unslightly in females. In males, the enlargement can later produce a permanently painful area, if they are required to kneel in routines, because of its prominence. Continued active growth may prevent the student from catching up sufficiently with strengthening exercises.

TEACHER ALERT: This condition may pose a dilemma for the teacher. Even though the condition is not as dramatic and obvious as an injury, the teacher must nonetheless in good conscience tell the student and parents that a short rest period from dance classes is necessary until the growing pains subside. The teacher should attempt to keep the interest of the student and parents active during this period, indicating that this condition is temporary and that it does not mean the student's body is unsuited for dance. Try to give this student strengthening exercises yourself if the expense of a physiotherapist is not possible for the parents to assume.

When the student gradually returns to class allow for catch-up time on given material and be especially careful of proper alignment, especially with swaybacked knees.

As in all physical conditions, the evaluation of a doctor is required before you discuss corrective exercises.

RELATED ARTICLE: LIBLER'S EXERCISE FOR INNER THIGH MUSCLES

Sit on the floor, knees straight, and feet a few inches apart. Keeping this same position, rotate your big toes inward until they meet as you experience thigh muscles contracting, Hold for a few counts; release; repeat five or ten times.

To engage the quadricep muscles, do the exercise by assuming the same position while sitting on a chair with your legs extended, slightly above the floor.

William A. Liebler, M.D., is attending Orthopedic Surgeon, Department Of Orthopedic Surgery and Institute of Sports Medicine and Athletic Trauma, Lenox Hill Hospital, in New York City. He is also in private practice and has accumulated statistics for more than 1,000 injuries in dancers.