Electromyographic analysis of the anterior cruciate ligament-deficient knee.

The protective relationship of the human anterior cruciate ligament (ACL) by active contraction of the hamstring musculature has been known and understood by sports orthopedists and physical therapists for many years. Rehabilitation programs for patients with torn ACLs as well as those treated with ligament reconstruction have always stressed hamstring strengthening. Research in this area during the past decade has begun to define the proprioceptive mechanism that governs this relationship as well as the actual recording of dynamic muscle firing patterns in pre- and postoperative subjects. Laboratory studies suggest that altered hamstring activity may help these subjects compensate for a knee that is lax because of ACL damage.

Rehabilitation of the nonreconstructed anterior cruciate ligament-deficient knee.

Management of the patient with an ACL-deficient knee continues to be controversial. In the patient with an acute ligament disruption, arthroscopic examination if employed should be followed by a physical therapy program that restores not only range of motion and strength, but also prepares the athlete for the return to his sport. Patients with chronic ACL-insufficiency must be evaluated meticulously with regard to pain and instability with functional activities followed by a vigorous attempt at conservative care including bracing.

A biomechanical analysis of anterior cruciate ligament reconstruction with the patellar tendon. A two year followup.

Eleven patients, 2 years after ACL reconstruction with a patellar tendon graft, returned for follow-up testing consisting of: 1) subjective assessment and functional analysis, 2) objective examination for residual ligamentous instability, 3) isokinetic quadriceps and hamstrings strength assessment, 4) radiographic assessment, 5) instrumented measurement of anterior shear displacement via a knee arthrometer, and 6) force plate and film analysis while performing cutting maneuvers in a laboratory setting. All 11 patients had been tested preoperatively through all steps except the fifth. The group subjectively rated the postoperative knee as 83% of the preinjury status, an increase from a 53% mean prior to reconstruction. Six of 11 patients were able to return to their full preinjury level of competition, with or without a brace. Four patients had positive drawer tests, five had positive Lachman examinations, and all subjects had negative pivot shifts. Significant quadriceps torque deficits remained (P less than 0.0005), with the postoperative knee extensors approximately 85% of the contralateral limb. The involved limb hamstrings were equal in strength to the nonoperated limb. Radiographic evaluation revealed four, five, and four patients with positive findings of the patellofemoral joint, medial joint space, and lateral joint space, respectively. Only one patient had normal radiographs. Instrumented knee laxity testing revealed the operated knee to be significantly looser only during maximum passive displacement (7.2 mm versus 5.3 mm, P less than 0.01) and not during the other measurements. Biomechanical analysis of the straight cut maneuver revealed no significant differences between the nonoperated and operated limbs at the 2 year postoperative mark.(ABSTRACT TRUNCATED AT 250 WORDS)

Functional analysis of untreated and reconstructed posterior cruciate ligament injuries.

Twenty patients with old ruptures of the PCL were analyzed. Ten patients were untreated, and ten patients had reconstruction of the PCL with the medial head of the gastrocnemius. The patients' gait was analyzed using high speed photography, footswitches, electromyography, and force plate. Patients were studied while walking, running, and stair-climbing. A Cybex muscle strength evaluation was also performed. Clinically, all patients had moderate to severe posterior instability. Five of the 20 patients also had posterolateral instability. Cybex testing showed quadriceps deficits in both reconstructed and untreated groups when comparing involved and uninvolved limbs. The reconstructed group also had deficits on hamstring Cybex testing. Footswitch data showed only minimal abnormalities. Gait velocity of walking was 91% of normal with a normal cadence. There was no significant difference in the single limb support times between the involved and uninvolved limbs in walking, fast walking, or running. The photometric data showed a tendency for increased knee flexion during the midstance phase of the gait cycle in comparing involved and uninvolved limbs. The knee flexion angles during midstance were similar in the patients with posterior instability when compared to the patients with the additional posterolateral instability. Force plate data showed decreased foot-floor reaction in the untreated group during terminal stance while walking. Similar findings were found in the reconstructed group during running.(ABSTRACT TRUNCATED AT 250 WORDS)

Modification of quadriceps femoris muscle exercises during knee rehabilitation.

Rehabilitation of the quadriceps femoris muscle is the cornerstone of full recovery after inactivity, immobilization, or surgery of the knee. Muscle strengthening programs often are interrupted by patients' complaints of pain experienced during exercise, which frequently prolong the patients' convalescence period. Specific modifications of standard quadriceps femoris muscle exercises often allow completely pain-free exercise, thus providing a faster progression of treatment and a subsequently shorter rehabilitation period. The purposes of this article are to review briefly patellofemoral biomechanics as it relates to quadriceps muscle rehabilitation and to summarize several modifications that in our clinical experience repeatedly have reduced pain during exercise.

Functional analysis of anterior cruciate ligament instability.

Eighteen males and two females (mean age, 26.5 years) underwent biomechanical assessment and Cybex evaluation prior to ACL reconstruction. Clinically, all patients had at least a 1+ grade with the Lachman, anterior drawer, and pivot shift tests, the majority being graded as 2+. Footswitch, high speed photography, force plate, and indwelling wire electrode data were collected while each subject performed free and fast walking, running, cutting, and stair climbing activities. During walking, single limb support times did not differ between the subject's involved and uninvolved limbs. Knee joint angles were similar between limbs during walking, running, and stair climbing maneuvers. Dynamic EMG tracings during walking demonstrated similar quadriceps and calf activity between limbs, while greater variation in hamstring firing was evident among subjects. During running, the involved limb had a longer duration of medial hamstring activity compared to the lateral hamstring. No significant differences were seen in either vertical or sagittal shear forces during free walking. During fast walking, higher midstance vertical forces (F2) were present in the involved limb (P less than 0.05). During running, the involved limb experienced lower vertical forces (P less than 0.05), while both anterior and posterior sagittal shear differences were insignificant. Straight cut maneuvers demonstrated significantly lower lateral shear and vertical forces in the involved limb (P less than 0.05). Lower lateral and sagittal shear forces in the involved limb (P less than 0.01 and P less than 0.05, respectively), combined with a reduced angle of the cut during the cross-cut maneuver, may be the first means to assess the functional pivot shift phenomenon ever documented.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of knee extensor mechanism disorders: clinical presentation of 1 12 patients*.

Results of physical therapy evaluation of 112 patients with extensor mechanism disorders (chondromalacia patella, infrapatellar tendinitis, and peripatellar pain) are presented. An equal number of male and female patients were evaluated and of the 73 patients with unilateral involvement (65%) there were equal numbers of right and left involved knees. Running was the activity most commonly associated with pain, followed by basketball and tennis. Stairclimbing was painful in 79% of the patients, with ascending being more painful than descending in patients reporting a clear-cut difference. Hamstring and quadriceps tightness was statistically significant relative to the uninvolved limb although clinically, negligible differences were measured. The inferior pole of the patella was the most tender site to palpation, followed by medial peripatellar structures, then lateral sites. Biomechanical malalignment was not detected by the attending therapist in the majority of patients. The authors emphasize careful assessment of flexibility, quadriceps (VMOIVL) imbalance, and biomechanical alignment in performing a thorough evaluation of patients with extensor mechanism disorders. J Orthop Sports Phys Ther 1986;8(5):248-254.

Physical therapy treatment of knee extensor mechanism disorders: comparison of four treatment modalities*.

Fifty-three patients diagnosed as having one of several types of extensor mechanism disorders of the knee were randomly assigned to one of four treatment groups to assess the effects of one of four different modalities (ice, phonophoresis, iontophoresis, and ultrasound/ice contrast). Following four physical therapy treatments over a 10-day period, the group treated with the ultrasound/ice contrast demonstrated the greatest subjective improvement (47%). The pre- to post-treatment isometric strength resulted in a 28% improvement in knee extension strength and a 34% improvement in knee flexion strength. The authors emphasize that evaluation should include assessment of quadriceps tone and strength as well as careful palpation to determine the irritable structures. Ultrasound/ice is advocated as the most effective choice of the modalities tested for treatment of pain associated with extensor mechanism disorders. J Orthop Sports Phys Ther 1986;8(5):255-259.

Clinical presentation of osgood- schlatter disease in the adolescent population.

Osgood-Schlatter disease is a condition affecting knees of adolescents. Males are affected more frequently than females, and unilateral involvement is more common than bilateral. In the 75 cases seen in our clinic in 4l/3 years, participation in basketball was twice as common among our patients as was any other sport. With the addition of our clinical cases to those documented in the literature, the left knee is significantly more involved than the right (P < 0.05). Relationship to hand dominance is discussed as a possible explanation for the unusual prevalence for left knee involvement. J Orthop Sports Phys Ther 1985;7(1):1-4.

Osgood-schlatter disease: review of literature and physical therapy management.

Osgood-Schlatter disease is a traction apophysitis of the tibial tubercle, the weakest link of the extensor mechanism of the adolescent. Conventional medical treatment includes plaster casting, injections of various anti-inflammatories, and surgical removal of painful ossicles in resistant cases. While not a very common condition, Osgood-Schlatter disease is being seen with increasing frequency in teenage athletes, especially basketball players (Antich, Lombardo, J Orthop Sports Phys Ther 7: 1-4, 1985.) With a focus on muscular tightness as a possible causative factor, physical therapy evaluation is outlined, followed by techniques for pain control and stretching exercises for the quadriceps and hamstrings. Ice massage is advocated as a way for the athlete to treat postexertional discomfort in the area of the tubercle. The patient and his or her parents must be assured that while residual deformity may remain, disappearance of symptoms coinciding with closure of the apophyseal plate is often the end result.J Orthop Sports Phys Ther 1985;7(1):5-10.

Phonophoresis: the principles of the ultrasonic driving force and efficacy in treatment of common orthopaedic diagnoses.

Phonophoresis with antiinflammatories or local anaesthetics is utilized by physical therapists as part of their treatment plans. The physics of ultrasound and the mechanical, thermal, chemical, biological, and physiological effects on the body's tissues are reviewed. Experimental studies cited showed increased muscle and nerve cortisol concentration when a topical application is followed by ultrasound. Clinical studies demonstrate greater pain relief and functional range of motion improvement when treatment protocols opted for hydrocortisone phonophoresis as opposed to ultrasound. Phonophoresis is compared to iontophoresis as another means of driving a topically applied medication into the tissues, and the benefits of each are discussed. J Orthop Sports Phys Ther 1982;4(2):99-102.