STUDY DESIGN: Controlled laboratory study using a cross-sectional design. OBJECTIVES: To analyze lower extremity kinematics during takeoff of a “saut de chat” (leap) in dancers with and without a history of Achilles tendinopathy (AT). We hypothesized that dancers with AT would demonstrate different kinematic strategies compared to dancers without pathology, and that these differences would be prominent in the transverse and frontal planes. BACKGROUND: AT is a common injury experienced by dancers. Dance leaps such as the saut de chat place a large demand on the Achilles tendon. METHODS: Sixteen female dancers with and without a history of AT (mean ± SD age, 18.8 ± 1.2 years) participated. Three-dimensional kinematics at the hip, knee, and ankle were quantified for the takeoff of the saut de chat, using a motion analysis system. A force platform was used to determine braking and push-off phases of takeoff. Peak sagittal, frontal, and transverse plane joint positions during the braking and push-off phases of the takeoff were examined statistically. Independent samples t tests were used to evaluate group differences (α = .05). RESULTS: The dancers in the tendinopathy group demonstrated significantly higher peak hip adduction during the braking phase of takeoff (mean ± SD, 13.5° ± 6.1° versus 7.7° ± 4.2°; P = .046). During the push-off phase, dancers with AT demonstrated significantly more internal rotation at the knee (13.2° ± 5.2° versus 6.9° ± 4.9°; P = .024). CONCLUSION: Dancers with AT demonstrate increased peak transverse and frontal plane kinematics when performing the takeoff of a saut de chat. These larger displacements may be either causative or compensatory factors in the development of AT.

J Orthop Sports Phys Ther 2011;41(8):606-613, Epub 12 July 2011. doi:10.2519/jospt.2011.3580

KEY WORDS: ankle, biomechanics, dance, hip, leaps, saut de chat, tendon

The patient was a 14-year-old female with a 4-year history of left anterolateral foot and ankle pain of insidious onset that was first noticed while playing soccer. After a lack of progress with conservative measures for her left foot and ankle pain, the patient was evaluated by an orthopaedic surgeon. While conventional radiographs of the foot and ankle were normal, magnetic resonance imaging revealed generalized bone marrow edema in the navicular bone with irregularity along the lateral margin of the navicular bone and adjacent anterior margin of the anterior process of the calcaneus. These findings suggested possible sequelae of osteonecrosis or a partial coalition between the lateral margin of the navicular bone and anterior process of the calcaneus. Computed tomography scanning revealed focal osteochondral bone changes along the lateral margin of the navicular bone and anterior process of the calcaneus. Surgery was performed 3 months later, which involved excision of a fibrous calcaneonavicular tarsal coalition.

J Orthop Sports Phys Ther 2010;40(9):596. doi:10.2519/jospt.2010.0415

KEY WORDS: ankle, computed tomography, foot, magnetic resonance imaging

Several benefits have been identified for individuals who regularly participate in sports and exercise. Those benefits include, but are not limited to, reduced risk for premature death due to cardiovascular disease, increased bone density, reduction of hypertension and diabetes, improved weight and body fat control, and improved mental health. Increased sport participation, however, is also accompanied by increased risk of injury. Fortunately, many sports-related injuries are preventable, and physical therapists can play an important role in the education of athletes and the prevention of acute and chronic injuries. The main goal of this special issue is to provide up-to-date commentaries on a wide range of topics related to preventive sports medicine.

J Orthop Sports Phys Ther. 2003; 33(10):556.

Key Words: preventative sports medicine, exercise

Genu recurvatum is a common entity found in the clinic that may have negative consequence to knee structures. The purpose of this article is to review the anatomy, biomechanics, and clinical effects associated with genu recurvatum. Genu recurvatum is operationally defined as knee extension greater than 5°. Individuals who exhibit genu recurvatum may experience knee pain, display an extension gait pattern, and have poor proprioceptive control of terminal knee extension. An evaluative process and treatment program are discussed that include muscle imbalance correction, proprioceptive practice, gait, and functional training. Taping or knee bracing may be used initially to facilitate knee control. This article is intended to draw attention to patients with genu recurvatum and presents a suggested treatment progression. Individuals who are involved in athletic endeavors should be aware of knee position during activities to help protect joint structures.

J Orthop Sports Phys Ther. 1998;27(5):361-367.

Key Words: knee, genu recurvatum, anterior cruciate ligament, rehabilitation

Early in the postoperative period, changes in tibial translation have been noted in patient populations following anterior cruciate ligament reconstructive surgery. Deformation due to a lengthening of the ligament graft has been the most widely accepted reason for the change in tibial translation. Treatment techniques have not been proven successful in the abatement or reversal of this graft lengthening. The purpose of this study was to investigate the effect of functional bracing on tibial translation during the first year postoperatively in a group of patients with early changes in tibial translation. Three consecutive patients with early increases in KT-2000 manual maximum total drawer following bone-patellar tendon-bone allograft reconstruction were identified as subjects in the control group. Five consecutive anterior cruciate ligament bone-patellar tendon-bone allografts with early increases in KT-2000 manual maximum total drawer were identified as subjects in the treatment group. These patients were followed monthly during the first year postoperatively by manual maximum total drawer KT-2000 testing. Criteria for inclusion in the treatment and control groups included KT-2000 testing, with an increase in translation of greater than or equal to 2 mm when compared with the uninvolved knee during the first year postoperatively. The treatment group was required to wear a functional knee brace during all weight-bearing activities until KT-2000 displacement measures were stabilized for 3 consecutive months. Treatment with the functional brace resulted in a mean 2.3-mm decrease in tibial translation in the manual maximum total drawer KT-2000 when comparing the involved and uninvolved knee prebracing with posttreatment. All 5 subjects in the treatment group had a decrease in tibial translation. A Median Test comparing the control and treatment group's KT-2000 scores was significant at the p < .05 level. Patients who experience early increases in tibial translation with anterior cruciate ligament reconstructions may be assisted in a reduction of the displacement by the use of a functional brace.

J Ortho Sports Phys Ther. 1998;28(1):32-39.

Key Words: anterior cruciate reconstruction, functional bracing, creep

Female participation in athletics has increased dramatically over the last decade. Accompanying the increase in participation in sports is the increased incidence of anterior cruciate ligament (ACL) injury. The purpose of this study was to examine the correlation between static postural faults in female athletes and the prevalence of noncontact ACL injury. Twenty ACL-injured females and 20 age-matched controls were evaluated. Seven variables were measured: standing pelvic position, hip position, standing sagittal knee position, standing frontal knee position, hamstring length, prone subtalar joint position, and navicular drop test. A conditional step-wise logistic regression analysis revealed the factors of knee recurvatum, an excessive navicular drop, and excessive subtalar joint pronation to be significant discriminators between the ACL-injured and noninjured groups. These findings may have implications regarding rehabilitation techniques in physical therapy.

J Orthop Sports Phys Ther. 1996;24(2):91-97.

Key Words: anterior cruciate ligament, female athletes, postural faults