Resource Papers and Fact Sheets
Factors Affecting Turnout
Teachers encourage their students to turnout only from the hips, and as a working cue, this is sound advice. However, anatomically, there are contributions to a fully turned out leg that come from the structure of the knee and lower limb joints. Research suggests that on average, 60% of turnout is created by outward rotation of the hip. Twenty to thirty percent of turnout may then emanate from the ankle, with the remaining percentage created by the tibia and knee joint. For an understanding of how the lower leg contributes to turnout in the extended (standing) position, please read about the "screw home" mechanism in the section called Individual anatomical variations below. The limiting anatomical structures include bones, ligaments, the joint itself, and muscles surrounding the hip joint.
There are five main factors that affect turnout:
- Angle of femoral anteversion
On average, the neck of the femur is angled 15 degrees forward relative to the shaft of the femur (see Figure 9A). An increase in this anterior angulation, called anteversion, often will cause someone to toe in when they walk (see Figure 9B). This is often referred to as being pigeon toed. In children who are born with more anteversion, the orientation of the femoral shaft in the hip socket makes the knees face towards each other when standing or walking. In ballet class, when they turn out their legs from the hip, the knees face the front, leaving little additional hip rotation to create the expected angle of outward rotation visible at the feet.
However, a decrease in this angulation, called retroversion, will allow one to have greater turnout (see Figure 9C). Children born with retroversion have a much easier time with turnout. Just standing in parallel, the knees and feet tend to face outward. By adding external rotation at the hip, they can achieve a larger angle of outward rotation visible at the feet than the average person. Currently, most researchers agree that these are not conditions that can be altered with training.
- Orientation of the acetabulum
The socket of the hip faces out to the side and somewhat forward, but there are individual variances. The socket that tends to face more directly to the side with a less forward facing will allow a greater amount of turnout to come from the hip.
- Shape of the femoral neck
The neck of the femur is subject to some variability. A longer and more concave neck allows a greater range of motion at the hip; it is less likely to contact the outer edge of the acetabulum in turnout and is therefore considered to be advantageous. A shorter and less concave neck will have the opposite effect and limit turnout potential.
- Elasticity of iliofemoral or Y ligament
As previously mentioned, the three ligaments surrounding the hip restrict extension. The iliofemoral ligament, strong and with minimal elastic properties, opposes extension of the hip. This ligament also resists lateral rotation or turnout of the hip. Thus, the more the hip is extended to the back, the greater the resistance to turnout. It is controversial whether attempts should be made to alter the flexibility of this ligament, as it may alter its capacity to stabilize the hip. In order to gain greater turnout when standing, dancers sometimes flex the hips by tilting the pelvis forward. This flexed position creates some laxity in the ligaments, providing slack that can be used to increase hip rotation. However, this attempted compensation creates a position of lumbar lordosis (low back sway), thrusts the buttocks backward, and is aesthetically undesirable and potentially damaging. Additionally, with a pelvis in this tilted position, the angle for using the deep external rotator is less effective.
- Flexibility and strength of the muscle-tendon unit
The muscles surrounding the hip, if unnaturally tight, may restrict a dancer's ability to achieve an acceptable degree of turnout. Proper stretching techniques will enable dancers to achieve their maximal turnout potential. Similarly, adequate strength and optimal activation of the hip external rotators may help dancers to achieve their potential turnout. Part 2 of this resource paper, Turnout for Dancers: Supplemental Training, provides an array of exercises and images to enhance the flexibility, strength and motor control of the musculature that supports turnout.
Individual Anatomical Variations
Summative contributions of the hip, knee, tibia, and foot create the dancer's turnout. In most cases, dancers do not possess perfect turnout, or complete external rotation from the hip, without associated adjustments to support the rotation through the rest of the lower leg.
In weightbearing positions (standing), when the knee is straightening from a flexed position to full extension, the medial condyle stops moving before the lateral condyle. The result is that the femur inwardly rotates on the tibia in those last few degrees of extension. The knee joint is then in a locked position, known as the "screw home" mechanism. In essence, the lower leg and foot will now appear further externally rotated than the knee and thigh. When the knee initiates flexion, a small muscle at the back of the knee called the popliteus externally rotates the femur so that it can once again line up with the lower leg. Note that in the flexed knee, the lower leg can externally rotate because the primary ligaments are lax. It is unwise to rotate the lower leg in this manner, and then straighten the knee into standing. Examples of this action include the dancer closing a tendu into 5th position plié or shifting the heels forward at the base of a grand plié. This action of straightening the knee from the flexed, rotated position puts undue pressure on these protective ligaments.
At the tibia, torsion is defined as an axial twist of the tibia or shinbone. The twist can occur internally or externally. Internal tibial torsion occurs when the tibia medially rotates; this condition will adversely affect the ability of a dancer to achieve turnout. It is presumed that young dancers who have internal tibial torsion will self-select away from dance forms that require turnout due to frustration or pain in trying to achieve this goal. External tibial torsion has been measured as widely varied as 16-60 degrees. Further, dancers tend to have differing amounts of tibial torsion in each leg. This will mean that turnout on each leg will be varied. Most health care practitioners advise that one assumes the rotation of the less turned out leg for symmetry and injury prevention.
The small bones in the foot allow a gliding action to occur at the arch. It is not uncommon to see dancers force the lower limbs beyond the normal limits of the hip's range of motion, creating a compensating action called pronation or "rolling in" of the feet to achieve the perception of greater or perfect turnout. This is also referred to as "forcing the feet." Dancers are more prone to force the feet in 5th position than other leg positions. Naturally, abnormal alignment ensues, causing medial stress along the leg and knee, and is quite possibly linked to increased injury potential. The injury rate for the foot and ankle complex is the highest of all joint systems. Thus, this strategy of allowing the foot to pronate as a compensatory mechanism for turnout is discouraged by teachers and health care practitioners alike.
It is important to remember that external hip rotation and turnout are not the same thing. Turnout is understood to be a necessary component of many dance idioms. It is presumed to be "perfect" when each leg is rotated 90 degrees laterally. However, researchers agree that available external hip rotation coupled with the various contributions of the tibia and foot rarely add up to this magic number. As there is a vast array of individual differences in human bodies, there are many considerations in determining how to safely optimize turnout. As dance teachers and dancers learn the anatomical and biomechanical mechanisms underlying turnout, both general and individual, they will be more able to understand, evaluate and apply sound methods to improve turnout and optimize dynamic function.
In the resource paper, Turnout for Dancers: Supplemental Training, specific exercises for conditioning and recruitment of primary and supporting muscles involved in turnout are described. The paper also considers issues of core support and alignment as related to turnout.
This paper may be reproduced in its entirety for educational purposes, provided acknowledgement is given to the "International Association for Dance Medicine and Science."
Copyright © 2011 IADMS, Virginia Wilmerding, Ph.D., and Donna Krasnow, M.S.