Multi-Segment Assessment of Ankle and Foot Kinematics during Relevé Barefoot and En Pointe

• Published in: Orthopaedic physical therapy practice Vol. 32; no. 3; pp. 167 - 175
• Main Authors: Veirs, Kimberly P, Baldwin, Jonathan D, Rippetoe, Josiah, Fagg, Andrew, Haleem, Amgad, Jeffries, Lynn, Randall, Ken, Sisson, Susan, Dionne, Carol P
• Format: Magazine Article
• Language: English
• Published: La Crosse Academy of Orthopaedic Physical Therapy 01.07.2020
• Subjects: Ankle; Ballet; Biomechanics; Dance; Dancers & choreographers; Injuries; Kinematics; Motion capture; Orthopedics; Physical therapy
• ISSN: 1532-0871

Three-dimensional (3D) motion capture systems are valid and reliable tools that have the capacity to record in vivo kinematics of the ankle and foot in all three planes of movement (sagittal, frontal, and transverse) during gait and other dynamic movements using reflective tracking markers.8,9 Much like sports medicine, dance medicine researchers are using whole-body 3D motion capture technology as an initial assessment tool to describe biomechanics unique to the dance population and ascertain risk for injury.4 Yet, there is a dearth of literature describing the in vivo kinetics and kinematics of the foot-complex during fundamental dance-specific movements, limiting the clinician's ability to adequately evaluate dancers' technique. The foot and ankle are assessed during whole-body motion capture to varying degrees of specificity based on the number and placement of reflective tracking markers.9 The number and placement of tracking markers on anatomical landmarks create a biomechanical model used for analyzing in vivo kinematics.10 The 3D single-segment foot models combine the foot-ankle complex into one rigid body whereas 3D multi-segment foot models (3DMFM) allow for evaluation of the foot segments separate from the ankle joint.9,10 Thus, a comprehensive evaluation of the dancers' foot-complex separate from the ankle joint requires evaluation of dancespecific movement using a 3DMFM.8 Carter et al11-13 were the first to analyze dance-specific movement using a 3DMFM by modifying 6 components of the Rizzoli foot model (RFM) on barefoot dancers. Additionally, the RFM demonstrated repeatability thresholds that are consistent with BF findings when applied to a shoe during gait.22 Because dance-specific movement requires extreme ROM to perform correctly3,7,11,23 (eg, ankle PF and hallux extension in BF relevé), the RFM required modifications to design the BF and shod dance-specific models. Seventy-six reflective skin-mounted anatomical markers and two sets of cluster tracking markers affixed in the same stepwise fashion using double-sided tape enabled whole-body recording of in vivo motion-related data.4 Forty of the reflexive markers were secured to the trunk and pelvis (sternum, R/L acromions, C7, R/L infrascapular angles, L3, R/L posterior superior iliac spines, R/L iliac crests, R/L anterior superior iliac spines [ASIS], and the apex of the sacrum), the upper extremities (R/L humeri, R/L medial and lateral epicondyles, R/L olecranons, R/L radii, and R/L ulnas), and the lower extremities (R/L greater trochanters, R/L thigh at the midpoint between the ASIS and superior apex of the patella, R/L lateral and medial condyles, R/L tibial tubercles, R/L fibular heads, and R/L shank at the midpoint between the tibial tubercle and ankle joint).