Affiliations: University of Miami School of Medicine, Division of Physical Therapy, Coral Gables, FL, USA
Correspondence:
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Address correspondence to: Ira M. Fiebert, Ph.D., P.T., University of Miami School of Medicine, Division of Physical Therapy, 5915 Ponce de Leon Boulevard, Plumer Building 5th Floor, Coral Gables, FL 33146-2406, USA. Tel.: +1 305 284 4535; Fax: +1 305 284 6128; E-mail: [email protected].
Abstract: The purposes of this investigation were: 1) to determine whether cervical range of motion and strength differ when measured in resting head posture (RHP) vs. neutral head posture (NHP), 2) to examine gender differences in cervical range of motion, strength, and neck girth, and 3) to examine the relationship between cervical range of motion and strength with: a) neck girth, b) height, and c) weight. Forty-six graduate students (10 males, 36 females) age 20–40 with no history of cervical or shoulder girdle pathology were recruited. Height, weight, and neck girth were measured for each subject. The Cervical Range of Motion (CROM) device was used to determine the amount of forward head posture and active range of motion for flexion (FLEX), extension (EXT), right and left lateral flexion (RLF and LLF), and right and left rotation (RROT and LROT) with subjects seated in a straight-back chair. Isometric cervical strength for FLEX, EXT, RLF, LLF, RROT, and LROT was then determined using the Microfet hand-held dynamometer with subjects seated in a chair which stabilized the trunk. Subjects performed the six active range of motion and the six isometric contractions in the RHP and NHP. Greater range of motion for EXT was achieved in the NHP, while greater RLF, RROT and LROT was achieved in the RHP. LROT in the RHP was the only contraction to demonstrate significantly greater strength. Females had greater cervical extension than males in both postures. Males were consistently stronger than females for all contractions in both postures and had larger neck girths. Strength correlated with neck girth, weight, and then height.
Keywords: range of motion, isometric strength, postures
