title: Effects of hip and head position on ankle range of motion, ankle passive torque, and passive gastrocnemius tension.
abstract: Ankle joint range of motion (ROM) is notably influenced by the position of the hip joint. However, this result remains unexplained. Thus, the aim of this study was to test if the ankle passive torque and gastrocnemius muscle tension are affected by the hip and the head positions. The torque and the muscle shear elastic modulus (measured by elastography to estimate muscle tension) were collected in nine participants during passive ankle dorsiflexions performed in four conditions (by combining hip flexion at 90 or 150°, and head flexed or neutral). Ankle maximum dorsiflexion angle significantly decreased by flexing the hip from 150 to 90° (P < 0.001; mean difference 17.7 ± 2.5°), but no effect of the head position was observed (P > 0.05). Maximal passive torque and shear elastic modulus were higher with the hip flexed at 90° (P < 0.001). During submaximal ROM, no effects of the head and hip positioning (P > 0.05) were found for both torque and shear elastic modulus at a given common ankle angle among conditions. Shifts in maximal ankle angle due to hip angle manipulation are not related neither to changes in passive torque nor tension of the gastrocnemius. Further studies should be addressed to better understand the functional role of peripheral nerves and fasciae in the ankle ROM limits.
authors: EA 4334, Laboratoire "Motricité, Interactions, Performance", Université de Nantes, Nantes, France.|CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Dafundo, Portugal.
authors: R J
authors: RJ
authors: Andrade
authors: EA 4334, Laboratoire "Motricité, Interactions, Performance", Université de Nantes, Nantes, France.
authors: L
authors: L
authors: Lacourpaille
authors: CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Dafundo, Portugal.
authors: S R
authors: SR
authors: Freitas
authors: Health & Rehabilitation Research Institute, School of Rehabilitation and Occupation Studies, Faculty of Health and Environmental Studies, Auckland University of Technology, Auckland, New Zealand.
authors: P J
authors: PJ
authors: McNair
authors: EA 4334, Laboratoire "Motricité, Interactions, Performance", Université de Nantes, Nantes, France.
authors: A
authors: A
authors: Nordez
mesh_terms: D000328:Adult; D000843:Ankle Joint / Q000502:physiology*; D055119:Elastic Modulus / Q000502:physiology*; D004576:Electromyography; D016552:Ergometry / Q000295:instrumentation / Q000379:methods; D006257:Head; D006621:Hip Joint; D006801:Humans; D008297:Male; D053581:Muscle Strength Dynamometer; D009129:Muscle Tonus / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology*; D019415:Torque; D014463:Ultrasonography / Q000295:instrumentation / Q000379:methods; D055815:Young Adult
keywords: Stretching; elastography; fascia; flexibility; muscle; neurodynamics; range of motion; sciatic nerve; supersonic shear imaging