Dance involves patterned and rhythmic body movements, usually performed to music, that serve as a form of expression or communication. There are many different types of dances, including ceremonial, folk, ballroom, classical ballet, modern dance, jazz, flamenco, tap and so forth. Each of these has its unique movements and physical demands. Audiences associate dance with grace and enjoyment, yet very few people regard dance as one of the most demanding and strenuous athletic activities. Sixty-five to 80% of dance-related injuries are in the lower limbs, out of which about 50% are in the foot and ankle (Arheim 1986). Most of the injuries are due to over-use (about 70%) and the rest are of the acute type (ankle sprain, fractures and so on).
Dance medicine is a multidisciplinary profession because causes of injuries are multifactorial and hence treatment should be comprehensive and take into consideration the specific needs of dancers as artists. The goal of the treatment should be to prevent potentially dangerous specific stresses, allowing the dancer to keep active, acquiring and perfecting physical creativity and psychological well-being.
Training should preferably start at an early age in order to develop strength and flexibility. However, incorrect training results in injury to young dancers. Proper technique is the main concern, as incorrect posture and other bad dancing habits and methods will cause permanent deformities and over-use injuries (Hardaker 1987). One of the most basic movements is the turn-out—opening of the lower limbs outwards. This should take place in the hip joints; if it is forced more than the anatomic external rotation these joints will allow, compensations occur. The most common compensations are rolling-in of the feet, internal flexing of the knees and hyperlordosis of the lower back. These positions contribute to deformities such as hallux valgus (displacement of the great toe towards the other toes). Inflammations of tendons such as the flexor hallucis longus (the tendon for the great toe) and others may also result (Hamilton 1988; Sammarco 1982).
Being cognizant of individual anatomic differences in addition to the unusual biomechanical loads, such as in point position (standing on the tip of the toes), allows one to take actions to prevent some of these undesired outcomes (Teitz, Harrington and Wiley 1985).
The environment of dancers has great influence on their well-being. A proper floor should be resilient and absorb shock to prevent cumulative trauma to the feet, legs and spine (Seals 1987). Temperature and humidity also influence performance. Diet is a major issue as dancers are always under pressure to keep slim and look light and pleasing (Calabrese, Kirkendal and Floyd 1983). Psychological maladjustment may lead to anorexia or bulimia.
Psychological stress may contribute to some hormonal disturbances, which may present as amenorrhoea. The incidence of stress fractures and osteoporosis may increase in hormonally imbalanced dancers (Warren, Brooks-Gunn and Hamilton 1986). Emotional stress due to competition between peers, and direct pressure from choreographers, teachers and directors may enhance psychological problems (Schnitt and Schnitt 1987).
A good screening method for both students and professional dancers should detect psychological and physical risk factors and avoid problems.
Any change in activity levels (whether return from a holiday, sickness or pregnancy), intensity of work (rehearsals before a premiere tour), choreographer, style or technique, or environment (such as floors, stages or even type of dance shoes) makes the dancer more vulnerable.