Effects of cervical muscle fatigue on the perception of the subjective vertical and horizontal

Abstract

IntroductionCervical functional capacity outcome measures that are simple and reliable are urgently needed in order permit accurate assessment/reassessment during treatments and rehabilitation. Induced neck muscle fatigue has been shown to alter functional capacities such as balance and kinaesthetic sense in the standing posture. The Rod and Frame Test has also shown promise as a method of assessing the effects of chronic neck pain and injury, but currently only in the sitting position. The objectives of this project were therefore 1) to validate the computerised rod and frame test in the standing posture, and 2) to measure the effects that different cervical muscle fatigue protocol would have on the assessment of the subjective visual vertical and horizontal.MethodThe validation of the standing computerised rod and frame test in the standing posture was obtained by comparing results (n = 74) between the sitting and standing positions with the Spearman’s correlation coefficient. In addition, agreement between the two methods was analysed with the Bland-Altman method.Participants (n = 56) resisted with their neck muscles approximately 35% maximum isometric voluntary contraction force for 15 minutes on a purpose built apparatus in eight different directions. Wilcoxon signed rank tests analysed changes in horizontal and vertical rod and frame test between the neutral and all different directions of contraction. The changes of recorded unsigned vertical and horizontal errors for the combined frame condition in all situations of isometric contraction were analysed with two respective one-way repeated measures analysis of variance (ANOVA).DiscussionThe Spearman’s rho and Bland-Altman plots show that the Rod and Frame Test works equally well in sitting and standing positions.After muscle contraction, there were significant increases in error in all participants for both horizontal and vertical rod and frame tests, except after flexion. These errors were predominantly present after fatigue of muscles in the coronal plane of contraction. Proprioception alone cannot explain the difference in the rod and frame results between different muscle groups. It is suggested that an evolutionary advantage of developing improved subjective verticality awareness in the same direction as the main visual field could explain these findings.

Misperception of Visual Verticality Measured with a Virtual Reality Device in Patients with Fibromyalgia Syndrome: A Cross-Sectional Study

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Epigenetic inactivation of ST6GAL1 in human bladder cancer

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Nicht zervikogener Schwindel, sondern Benigner Paroxysmaler Lagerungsschwindel

“…In vielen Studien wird jedoch gezeigt, dass die HWS einen Einfluss auf die Okulomotorik 43 , 44 , 45 , 46 , 47 , 48 , auf das Gleichgewicht 35 , 49 , 50 , 51 , 52 , 53 , 54 , 55 und auf die Raumorientierung 48 , 56 , 57 , 58 , 59 hat. Ermüdbare oder ermüdete Nackenmuskeln können sowohl die Raumorientierung 60 als auch das Gleichgewicht 61 , 62 , 63 beeinflussen. Obwohl diese Zusammenhänge belegt sind, bleibt es schwierig, den zervikogenen Schwindel nachzuweisen, da es hierfür keinen eindeutigen Test gibt.…”