Reliability and agreement of a hand-held dynamometer in the assessment of neck muscles maximal voluntary strength

Abstract

Reliable measurements of neck muscles strength is mandatory to a proper kinetic and functional diagnosis and, consequently, to establish better physical therapy interventions programs for subjects with specific dysfunctions at cervical segment, for example women with migraine. In the context of the challenge to assess neck muscles strength at clinical practice, the use of a hand-held dynamometer seems to be a feasible option due to its easy handling and low cost accessibility. However, measurement properties of this tool to cervical segment evaluation have not been tested yet. The objective is to verify reliability and agreement of the Lafayette Manual Muscle Testing System to evaluate neck muscles maximal voluntary strength in migraine and headache-free women. To verify the interexaminer reliability, two examiners will assess subjects at the same day with a 10 minutes interval between assessments. To verify intraexaminer reliability, subjects will be assessed by the same examiner with a one week interval. Peak force of cervical flexion, extension and lateral flexion will be measured at a drawing sequence, and the same order of movement will be kept for each subject at the three tests. Intraclass correlation coefficient will be calculated to determine inter and intraexaminer reliability and standard error measurement to determine proposed assessment agreement.