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Background and aim: The function of deep neck flexor muscles is very important in physiotherapy assessments. The purpose of this study was to examine the reliability of sphygmomanometer device to measure the strength of deep neck  muscles.

Materials and methods: Thirty healthy non-athlete females aged 18-24 years old voluntarily participated in this study. The maximal contraction of deep neck muscles were measured in different times, different days and by two different testers using a sphygmomanometer device. At each session subjects performed three maximum voluntary contractions and the maximum strength was chosen for data analysis. The Interclass Correlation of Coefficient (ICC), Pearson product moment and CV% were used to assess the reliability of different measurements between times, days and two different examiners.

Results: The results of ICC, Pearson product moment and CV% indicated that the strength measurement of cervical stabilizer muscles were highly repeatable between different times, days and testers (ICC ≥ 0.90, CV% ≤ %3.8 and r ≥ 0.91).

Conclusion: The sphygmomanometer and the method which was used in this study appeared to be a reliable and useful method to measure the force of deep neck flexor muscles. It can also be suitable for the assessment of physiotherapy or rehabilitation programs.

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Backgroung and aim: Neck pain is one of three common complains of neuromuscular system. There are three subsystem to maintain stability of spine: passive subsystem, active (muscles) subsystem and control subsystem. Detection of postural muscle response during postural perturbation like fast arm movement can be utilized to analyse of postural control. Wearing cervical collars is a way to prevent or cure cervical pain. The aim of the present study was to investigate the effect of soft cervical collar on movement response and duration of activity and recruitment pattern of cervical muscles. 

Materials and methods: Twenty healthy young women participated in this study. They flex right shoulder in response to sound stimulus with and without wearing soft cervical collar. Surface Electromyography (EMG) used to assess postural muscle activity in following muscles: Deltoid , Trapezius , Cervical Erector spinae and  Sternocleidomastoid. The effect of soft cervical collar on reaction time, onset and duration of activity of cervical muscles was calculated.

Results: Wearing soft cervical collar increased reaction time of arm flexion  (P< 0.05) and decreased duration of activity of cervical extensor, trapezius and erector spinae (P< 0.05). During shoulder flexion with additional load, onset activity of trapezius muscle was significantly earlier than other neck muscles but cervical erector spinae and sternocleidomastoid exhibit coactivation pattern in response to perturbation .

Conclusion: During fast arm movement that leads to postural perturbation, soft cervical collar alleviates the response and reduce activity of muscles. The strategy of motor control centers in response to perturbation in cervical spine is coactivation of flexor and extensor muscles to maintain stability.