Dance Anatomy & Kinesiology

328 Dance Anatomy and Kinesiology

MTP joint is generally in fixed hyperextension and

both IP joints are in fixed flexion as seen in figure 6.31.

With hammertoes, the MTP joint is generally in fixed

hyperextension, the proximal IP joint is in fixed flex-

ion, and the distal IP joint is in hyperextension such

that the tip of the toe becomes depressed downward

(Levangie and Norkin, 2001; Mercier, 1995). These

conditions are commonly associated with pes cavus

in which the exaggerated arch involves a lowering of

the heads of the metatarsals relative to the rearfoot.

These conditions tend to place excessive stress on

the metatarsal heads, can interfere with balance and

placement on demi-pointe and pointe, and leave the

flexed joints vulnerable for blisters and corns.

It is important for dancers and teachers to realize

that these conditions are generally due to shortened

toe flexors or intrinsic muscle imbalance, and relax-

ing the toes will not produce the desired correction.

However, aggressive daily stretching by using one

hand to bring the toes (appropriate IP joints) into

extension while holding the MTP joint in a neutral

position can sometimes offer gradual but notice-

able improvement. In addition, using the intrinsic

interossei and lumbrical muscles to stabilize the MTP

joint in a neutral versus hyperextended position can

also decrease clawing during standing flat versus on

demi-pointe or pointe (Levangie and Norkin, 2001).

These muscles can create the desired flexion of the

MTP joint without producing undesired further

IP flexion of the toes. Furthermore, the extrinsic

and intrinsic toe extensors can be used to actively

extend the toes as much as the flexion contractures

will allow. Strength and use of these muscles can be

improved with doming exercises performed sitting

(table 6.6J, p. 349), followed by repetition of the

exercise standing, focusing on very slightly lifting the

metatarsal heads up (vs. letting them drop) as the toes

reach forward (IP extension). Mild deformities can

also sometimes be improved or relieved with over-and-

under taping to adjacent toes, selection of dance and

street shoes that are not too short, use of various pads

or toe caps to avoid pressure sores and corns from the

associated abnormal friction from shoes, and making

sure that the dancer is standing with his or her body

weight appropriately positioned (vs. too far back) so

that the toe flexors are not having to be used exces-

sively to maintain stability. Although in the general

population, surgery may be recommended for resis-

tant forms of these deformities, this type of surgery

is generally not recommended for the dancer.

Hallux Valgus and Bunions

Hallux valgus (L. great toe + turned outward) is a

lateral deviation of the distal end of the great toe

(hallux) at the MTP joint, often also involving a

deviation of the first metatarsal toward the midline of

the body (metatarsus primus varus) as seen in figure

6.32. This bony deviation changes the line of pull of

the muscles that cross the MTP joint, such that many

of these muscles will tend to have a bowstring effect

that further increases the valgus deformity, and in

more advanced cases causes the sesamoids to displace

to the lateral side of the head of the first metatarsal.

This valgus deviation of the hallux also tends to

make the medial aspect of the first metatarsal head

become more prominent, and the resultant friction

and trauma from overlying footwear can readily lead

to a bony outgrowth (exostosis), an inflamed bursa

between the exostosis and skin, and a callus on the

overlying skin. This bony and soft tissue enlargement

on the inside of the head of the first metatarsal is

termed a bunion.

Hallux valgus has been reported to affect as many

as 22% to 36% of adolescents; a greater prevalence is

in active females, and particularly female ballet danc-

ers (Kravitz et al., 1986; Omey and Micheli, 1999).

The etiology is still controversial, but it likely involves

both familial factors and other factors that tend to

increase lateral deviation forces on the hallux such

as tight shoes, pointe work, metatarsus primus varus,

pes planus, excessive pronation, forcing turnout, and

joint hyperlaxity. In early stages, use of shoes with

a wider toe box, a felt pad, a toe separator, hallux

valgus taping, control of pronation, and strengthen-

ing the arch muscles and the abductor of the hallux

may give some relief. However, in later stages, loss of

FIGURE 6.31 Claw toes associated with pes cavus

(right foot, medial view). (A) Hallux, (B) second toe.