Original Article Measuring Functional Range of Motion in Ballet Dancers’ Hips Suzanne C. Martin, M.A., M.P.T., Felix A. Marquez, M.P.T., Margie A. Ordonio, M.P.T., and Diane D. Allen, M.S., P.T. Abstract population are significantly different achieve maximal end range. They In this pilot study, values for functional from those of the ballet population and confirmed through the use of radi- range of motion (FROM) at the hip were are not an accurate representation of ography that extreme hip abduction assessed for six female elite ballet danc- a dancer’s requirements.1-4 Inaccurate must occur with progressive external ers ranging from 18 to 30 years of age. assessment of female ballet dancers, in rotation to avoid contact of the greater The feasibility of the MOM© method particular, may result in losses for the trochanter against the ilium. Once of hip FROM goniometric assessment dancer. What appears to be adequate maximal external rotation ROM is was determined so that it might be used ROM using standard normative achieved, slight flexion is required to to create normative tables of FROM for values may ultimately mean either avoid possible impingement of the this population. Results indicate that four injury or loss of a contract for that femoral neck on the posterior wall of out of five end-positions were found to 5 5 be reliably reproducible, and reliability dancer. Although the same issues the acetabulum. across the three investigators was within pertain to the male, this study is One way of measuring ROM while clinically accepted values for four out of focused on the female population. accounting for combined movements five end positions. A preliminary norma- Most ballet hip ROM data has in diagonal planes is to measure while tive hip FROM table was generated that been collected using the standard go- the subject is in a functional upright revealed both high and low FROM values niometric technique, which prescribes position. Although there are no within as well as across dancers. recumbent or sitting positions and studies in the current literature that simple movements in cardinal planes.6 measure ROM of ballet dancers in he athletic and aesthetic Ballet movements, however, are ex- ballet positions, Pink and coworkers8 demands of ballet require full ecuted using combined movements did study lower extremity ROM of external rotation of the hips, in diagonal planes. For example, 14 recreational runners during the T 7 flexibility of the joints, and strength Kushner and colleagues, in a study four phases of gait. They stated that at an extreme range of motion of 22 professional ballet dancers, knowledge of functional ROM mea- (ROM), particularly in the case of reported that hip abduction dance surements would aid the health care the professional female ballet dancer. movements are done with external provider when asking the question, The ROM norms for the average rotation, as well as slight flexion, to “When does it hurt?”8 Measuring ROM in a functional position may Suzanne C. Martin, M.A, M.P.T., is an Intern in the Department of Physical assist the physical therapist in isolat- Therapy at Kaiser Permanente, Hayward, California. ing the occurrence of musculoskeletal symptoms during actual dance move- Felix A. Marquez, M.P.T., is an Intern in the Department of Physical Therapy at ments. Kaiser Permanente, Hayward, California. Although the subjects were not in Margie A. Ordonio, M.P.T., is an Intern in the Department of Physical Therapy functional positions, standardized go- at Sutter Hospital, Redwood City, California. niometric testing does have certain ad- Diane D. Allen, M.S., P.T., is an Adjunct Assistant Professor in the Department vantages. Measurement of joint ROM of Physical Therapy, Samuel Merritt College, Oakland, California. using the universal goniometer has content validity and, in some cases, Correspondence and reprint requests: Suzanne C. Martin, M.A, M.P.T., 1512 criterion-related validity when com- Sherman Street, Alameda, California 94501. pared with radiography.9 Reliability 56 Journal of Dance Medicine & Science Volume 2, Number 2 1998 57 Table 1 Table of Anatomical Landmarks Dancer’s Movement/ Stationary Moving Measurement End Position Fulcrum Arm Arm 1. Hip Flexion with développé en avant/ greater trochanter aligned with lateral condyle slight adduction and quatrième devant en l’air of the femur plumb line of the femur external rotation (ER) 2. Hip Abduction with développé à la seconde/ ASIS aligned with medial condyle slight flexion and ER à la seconde en l’air plumb line of the femur 3. Hip Extension and battement tendu derrière/ greater trochanter aligned with lateral condyle adduction with ER quatrième derrière au terre of the femur plumb line of the femur 4. and 5. Hip Rotation rotation/ internal and mid-calcaneus 0° line drawn on line from external rotation of gesturing foot paper protractor calcaneus to second toe of gesturing foot can also be achieved with the universal Methodology the goniometer during the développé goniometer when examiners are con- Subjects en avant (hip flexion) and développé sistent in lining up the fulcrum and à la seconde (hip abduction) as well both arms with established anatomical Six subjects from the Lawrence Pech as the battement tendu derrière (hip landmarks while subjects are placed in Dance Company, a San Francisco extension). In addition, the protrac- well-defined positions. This consis- professional ballet company, were tor of the goniometer was covered tency and use of a 0° and 180° nota- measured in order to satisfy inter-rater with paper, as suggested in a study tion system has resulted in “normal” and intra-rater reliability data analysis by Horger,11 so that the measuring 10 values as described by authorities such criteria. The six dancers were current examiner could not bias intra-tester as the American Medical Association members of the company, had actively or inter-tester reliability. (AMA) and the American Academy performed in the past three months, A hip rotation guide was devised of Orthopedic Surgeons (AAOS).9 and had no known structural deformi- in order to measure hip rotation in a If specific anatomical landmarks and ties or injuries in the hip. standing position. An 18 by 24 inch well-defined functional positions are Instrumentation piece of newsprint paper was taped to used when measuring a dancer’s hip, the dance floor. It served as a landmark functional hip ROM norms for the The instrumentation used was a for positioning dancers in relation to ballet population may be established, universal long-arm goniometer that the cameras, a standard for orientation with comparable reliability. was adapted to have a rigid z-axis of the dancer’s body to the barre and This pilot study was undertaken perpendicular to the plane formed the room, and as a rotation measure- in preparation for a larger study. The by the stationary and moving arms ment guide. larger study will seek to establish in the x- and y-axes. It also had a Masking tape was attached to the a table of normative values of hip plumb line attached at the fulcrum following bony landmarks to ensure FROM for female ballet dancers in in order to line up the baseline of the the greatest goniometric reliability: common dance positions. The pilot stationary arm with a vertical line. the anterior superior iliac spine (ASIS) study assessed the feasibility of the The rigid z-axis was aligned with the bilaterally, the ipsilateral ischial tuber- instrumentation and the procedures, ASIS of the dominant gesturing leg osity of the measured lower extremity, while also providing an analysis of to accommodate measurement of the medial and lateral condyles of the inter-rater and intra-rater reliability. A hip abduction during the développé femur, the greater trochanter of the preliminary normative table was also à la seconde. The plumb line ensured femur, and the center of the most prepared. verticality of the stationary arm of distal portion of the calcaneus and second toenail of the foot. Only the dominant gesturing lower extremity Table 2 Investigators’ Roles and Order of Rotation for Each Role was taped and measured. Role 1st rotation 2nd rotation 3rd rotation Two video cameras and one still camera were used to provide observa- Examiner 1 / measure Investigator 1 Investigator 3 Investigator 2 Examiner 2 / cameras Investigator 2 Investigator 1 Investigator 3 tion of the examiners’ measuring tech- Examiner 3 / recorder Investigator 3 Investigator 2 Investigator 1 niques as well as to observe postural deviations of each subject during the 58 Journal of Dance Medicine & Science Volume 2, Number 2 1998 Figure 1 End position 1 — quatrième Figure 2 End position 2 — à la seconde Figure 3 End position 3 — quatrième devant en l’air. en l’air. derrière au terre. Figure 4 End position 4 — external rotation. Figure 5 End position 5 — internal rotation. N = 0° line. measurements of each position. The dancer was then instructed to as shown in Table 2. Procedure assume position on the paper protrac- Examiner 1 lined up the arms of tor positioned on the floor. Figures 1 the goniometer on the subject three The pilot study included six 30-min- through 5 show Positions 1 through times in three distinct trials in each ute measurement sessions. Each 5, respectively. The MOM Method position, then handed the covered dancer was assigned a code number of FROM hip joint measurement, goniometer to Examiner 3 to read. and was given the opportunity to using the parameters listed in Table 1, Examiner 2 operated the video re- warm up as desired. The subjects’ was then performed on the standing corders and still camera. Examiner anatomical bony landmarks were dancer. 3 gave the dancer verbal instructions taped as discussed in the Intrumenta- The examiners rotated among three and recorded Examiner 1’s measure- tion section.