Endurance test of extensor muscles of the neck: Improve usability with a modification of applied load

Abstract

The endurance of extensor muscles of the neck has an important impact on functional status. Neck pain, cervical whiplash and few rheumatisms cause alteration of neck muscle performance. Harms-Ringdahl has designed a clinical test to assess endurance capability. If this test has good metrologic characteristics, unfortunately this method needs long time (6 min) to check if the patient reaches normal performance threshold. Because of this, physiotherapists don’t use this test in current practice. The aim of this study was to determine, by using various weights, which is the best one to estimate the cervical extensor endurance with short time cost. The second goal was to evaluate the link between endurance performances of extensor muscles and anthropometric characteristics. Twenty-five healthy volunteers were recruited. We successively measured the holding time to the endurance test of cervical extensors (ETCE). Three different loads were used in randomized order: 2 kg (original method of Harms-Ringdahl), 4 kg and 6 kg. The tests were interrupted after 900 sec. Age and anthropometric data (height, weight, neck length and cervical circumference) were noted. Non-parametric statistical tests were used. Finally, 15 women and 10 men participated. They were 21.7 ± 2.0 years old (m ± SD). Height, weight, neck length and cervical circumference were respectively: 170 ± 9 cm; 63 ± 10 kg; 12.8 ± 1.6 cm and 34.0 ± 2.7 cm. We found significantly different medians for the holding time ( P = 0.001): 900 sec [191–900] (median [min–max]); 350 s [121–900] and 209 sec [65–467], respectively for 2, 4 and 6 kg. Moreover, we found out that the holding times were correlated between them (0.67). Increase load in used of ETCE seems to be a relevant parameter to make this test less time-consuming. According to our results on healthy and young subjects, the 6 kg load is the most appropriate option for having an adequate holding time for clinical practice. However this weight remains to be tested on people experiencing non-specific neck pain and varied age groups.