Foot and ankle injuries in dancers

Dancing is not dangerous; however, dancers must recognize their limitations and learn to do the best they can with what they have to work with. This article discusses some of the more common acute and chronic foot and ankle problems in dancers for the benefit of the treating physician.     

Posterior ankle pain in dancers

Treatment of dancers can be as challenging as it is rewarding. Dancers often have unusual difficulties related to the altered kinesiology required by their individual dance form. A thorough understanding of these movements helps guide the physician to the cause of the disability, particularly in the setting of overuse injuries. This knowledge, coupled with a careful physical examination, is essential for the accurate diagnosis and treatment of the dancer, who is both artist and athlete.     

Foot and ankle biomechanics

With the advent of imaging advancements there has been renewed interest in the foot and ankle. However, many of the basic functions and biomechanical considerations of the bones, joints, and specialized tissues of the normal and dysfunctional foot and ankle remain unfamiliar to many radiologists. This article focuses on the basic biomechanics, normal alignment, and common alignment disorders of the foot and ankle that are relevant to radiologists.     

Stress fractures in ballet dancers.

We surveyed 54 female dancers in two professional ballet companies. A total of 27 fractures were reported in 17 dancers. Metatarsal fractures were the most common (63%), followed by fractures of the tibia (22%) and spine (7%). Dancers who danced greater than 5 hours per day were significantly more likely to have a stress fracture than those dancing less than 5 hours per day. Dancers in the stress fracture group also had a significantly longer duration of amenorrhea than those in the group with no stress fractures. No significant difference was found between the dancers who had stress fractures and those who did not with regard to any of the other variables examined. These data suggest that prolonged amenorrheic intervals and heavy training schedules may predispose ballet dancers to stress fractures. Of the 17 dancers with stress fractures, only 1 had neither of these risk factors.     

Foot and ankle injuries in dance

Acute traumatic injuries are common in ballet dancers. A careful history, thorough examination, and appropriate imaging should allow for the diagnosis of most problems. The clinician must have a high index of suspicion for occult bony injuries, especially if the patient fails to recover as expected. Aggressive treatment of the sprained ankle is essential to maintain foot and ankle mobility and prevent prolonged disability and subsequent overuse injuries. Kinetic chain dysfunctions are common in ballet dancers with overuse injuries and commonly follow ankle sprains. They may represent a secondary phenomenon that developed in response to the compensatory movement changes caused by the initial injury. It is important to remember, however, that these dysfunctions may have been long standing and a causative factor in the injury. Regardless of the time of onset of the dysfunction, residual kinetic chain dysfunction associated with incomplete rehabilitation of an injury may predispose the dancer to further injuries. Untreated dysfunctions at one site in the kinetic chain may predispose to compensatory dysfunction at other sites in the chain. Accordingly, it is essential to thoroughly examine the entire chain for functional movements when dealing with an injury, because identification and treatment of the kinetic chain dysfunction is important in the rehabilitation of the dancing athlete. Kinetic chain dysfunctions are common in injured ballet dancers and may be a cause of repeated injury. Why then are these dysfunctions left untreated? Medical personnel caring for dancers are sometimes guilty of tunnel vision, and focus solely on the injured site without considering what is happening at other sites in the kinetic chain. This oversight is compounded when the physicians or therapists are satisfied with discovering simply what injury has occurred rather than asking why the injury has occurred. The significance of kinetic chain dysfunctions is only just beginning to be recognized, and many examiners are not aware of the relationship between abnormal motion and injury. Generally, people see only what they look for, and they look only for what they know. Kinetic chain dysfunctions can easily be detected with simple tests of functional movement if the examiners include these tests in their assessment of the injured dancer. As long as clinicians are either unaware of or unwilling to perform these tests, these dysfunctions will remain untreated and may put the dancer at risk of failed rehabilitation or predispose them to further injury.     

Sensorimotor control is impaired in dancers with functional ankle instability

BACKGROUND: Factors potentially causing chronic instability after ankle inversion sprains have rarely been examined during the injuring movement. PURPOSE: To compare control of ankle movement during quiet stance and after inversion perturbation in chronically unstable ankles (n = 16) with healthy controls (n = 26). METHODS: Movement control was measured as magnitude of lateral ankle oscillation, using 3SPACE Fastrak during single leg stance (baseline oscillation) in two foot positions, flat and demi-pointe. In both positions, time to resume baseline oscillation after inversion perturbation (perturbation time) of 15 degrees for the flat foot and 7.5 degrees on demi-pointe was also determined. RESULTS: Baseline oscillation on demi-pointe was significantly smaller (P < 0.005) for the sprained group (2.5 +/- 0.5 mm) than for controls (4.0 +/- 2.3 mm). Perturbation time for the flat foot was significantly longer (P < 0.05) for the sprained group (2.2 +/- 0.4 seconds) than for controls (1.8 +/- 0.5 seconds). However, failure rate was higher (P < 0.05) among the sprained group than controls for perturbation with the foot flat and baseline oscillation on demi-pointe. CONCLUSIONS: Findings demonstrated altered sensorimotor control in chronically unstable ankles. Those sprainers who successfully completed the tasks minimized oscillation. The impairments in the sprained group may reflect deficits in either movement detection, peroneal muscle response, or both.     

Pictorial review: MRI features of foot and ankle injuries in ballet dancers

Foot and ankle pain is common in ballet dancers. Although clinical examination often points to the underlying cause, imaging is often necessary to confirm the diagnosis and thus ensure appropriate future management. Factors predisposing to the increased incidence of injuries in this population include the classical position in which ballet dancers stand, which is on the tips of the toes in the en pointe position or on the balls of the feet in the demi-pointe position. Furthermore, the repetitious nature of ballet and the long hours spent rehearsing cause over-use injuries. The causes of foot and ankle pain can be thought of in four different groups: the impingement syndromes; tendon abnormalities; osseous pathology; and ligament abnormalities. These will be discussed and illustrated.     

The effect of textured ballet shoe insoles on ankle proprioception in dancers

BackgroundImpaired ankle inversion movement discrimination (AIMD) can lead to ankle sprain injuries. The aim of this study was to explore whether wearing textured insoles improved AIMD compared with barefoot, ballet shoes and smooth insoles, among dancers.MethodsForty-four adolescent male and female dancers, aged 13–19, from The Australian Ballet School were tested for AIMD while barefoot, wearing ballet shoes, smooth insoles, and textured insoles.ResultsNo interaction was found between the four different footwear conditions, the two genders, or the two levels of dancers in AIMD (p > .05). An interaction was found between the four different footwear conditions and the three tertiles when tested in ballet shoes (p = .006). Although significant differences were found between the upper tertiles and the lower tertiles when tested with ballet shoes, barefoot and with smooth insoles (p < .001; p < .001; p = .047, respectively), when testing with textured insoles dancers in the lower tertile obtained similar scores to those obtained by dancers in the upper tertile (p = .911).ConclusionTextured insoles improved the discrimination scores of dancers with low AIMD, suggesting that textured insoles may trigger the cutaneous receptors in the plantar surface, increasing the awareness of ankle positioning, which in turn might decrease the chance of ankle injury.     

Instrumented measures of postural control in college dancers with and without chronic ankle instability

ObjectivesTo determine whether collegiate dancers with chronic ankle instability (CAI) demonstrated impaired postural control during instrumented measures of single-leg static balance compared to dancers without CAI.DesignCross sectional design.SettingUniversity dance studios.ParticipantsWe included N = 39 dance majors from a large, public university. We stratified participants into CAI (n = 20, age = 20 ± 1.8, IdFAI = 17.3 ± 5.7, number of sprains = 1.9 ± 1.1) and Control groups (n = 19, age = 20 ± 1.2, IdFAI = 2.5 ± 3.0).Main outcome measuresParticipants performed 3 x 10-s single-leg, static balance trials on a pressure mat in two different conditions, foot-flat eyes closed and demi-pointe eyes open. We measured six different time-to-boundary (TTB) measurements during each balance trial and calculated the average of the 3 trials for each condition. Participants also completed the Foot and Ankle Ability Measure (FAAM) sport and activities of daily living (ADL) questionnaires.ResultsThe CAI group reported greater IdFAI and lower FAAM-ADL and FAAM-Sport scores compared to the control group. We observed no significant differences in TTB measurements between the CAI and control groups during either balance conditions.ConclusionsInstrumented measures of static postural control were not impaired in college dancers with CAI compared dancers without CAI.     

Foot morphology and foot/ankle injury in indoor football

While the pronated foot is implicated as a risk factor for sports injury in some studies, others suggest that a supinated foot posture increases the risk of overuse lower limb injuries. Athletes in a given sports discipline may tend to have a similar foot morphology, which varies from that observed elsewhere. Further, the foot morphology that is beneficial for performance in a sport may be detrimental with regard to injury. Intra- and inter-rater reliability of the Foot Posture Index (FPI-6) as a measure of foot morphology was determined (ICC (2,1) 0.88 and 0.69 respectively). Thereafter, in a prospective cohort study using the FPI-6, 76 adolescent male indoor football (Futsal) players were measured and followed monthly over one competition season. Coach-rated ability and reports of any overuse injuries at the ankle and/or foot over this period were obtained. A significant negative linear relationship was found between the mean FPI-6 scores and coach-rated ability (p=0.008), with supinated and under-pronated postures related to higher ability level. Overall, 33% of injuries at the ankle and/or foot were classified as overuse. Foot Posture Index scores of less than 2, indicating the supinated and under-pronated feet, were found to be associated with a significant increase in the risk of overuse injury (p=0.008). The greater rigidity of these foot types may assist adolescent, male, indoor football players to perform at a higher level in their sport. Unfortunately, these players are also more likely to sustain ankle and/or foot overuse injuries.     

Frictional forces and ankle fractures in sport.

The frictional forces between the sports footwear and the ground can induce distorsion trauma to the lower extremity. Two cases are reported in which fractures about the ankle are related to this friction. An adjustment and reduction of the frictional forces are recommendable.     

Foot and ankle kinematics in patients with posterior tibial tendon dysfunction

The purpose of this study is to provide a quantitative characterization of gait in patients with posterior tibial tendon dysfunction (PTTD), including temporal-spatial and kinematic parameters, and to compare these results to those of a Normal population. Our hypothesis was that segmental foot kinematics were significantly different in multiple segments across multiple planes. A 15 camera motion analysis system and weight-bearing radiographs were employed to evaluate 3D foot and ankle motion in a population of 34 patients with PTTD (30 females, 4 males) and 25 normal subjects (12 females, 13 males). The four-segment Milwaukee Foot Model (MFM) with radiographic indexing was used to analyze foot and ankle motion and provided kinematic data in the sagittal, coronal and transverse planes as well as temporal-spatial information. The temporal-spatial parameters revealed statistically significant deviations in all four metrics for the PTTD population. Stride length, cadence and walking speed were all significantly diminished, while stance duration was significantly prolonged (p<0.0125). Significant kinematic differences were noted between the groups (p<0.002), including: (1) diminished dorsiflexion and increased eversion of the hindfoot; (2) decreased plantarflexion of the forefoot, as well as abduction shift and loss of the varus thrust in the forefoot; and (3) decreased range of motion (ROM) with diminished dorsiflexion of the hallux. The study provides an impetus for improved orthotic and bracing designs to aid in the care of distal foot segments during the treatment of PTTD. It also provides the basis for future evaluation of surgical efficacy. The course of this investigation may ultimately lead to improved treatment planning methods, including orthotic and operative interventions.     

Management of complex ankle fractures in athletes

Outcome from complex ankle fractures depends on the severity of the injury, the accuracy of the reduction, and the institution of soft-tissue rehabilitation. The timing of surgery must take into consideration the degree of soft-tissue swelling and the overall condition of the patient. Good operative technique is vital in preventing complications, restoring anatomic relationships, and obtaining rigid stability. In order to diminish time away from sports, the rehabilitation phase should overlap the healing phase.