In biomedicine, a joint that has a reduction in its ability to move is said to have a limited ‘range of motion’. The most common cause is a mechanical problem at the specific joint, most often seen in the arthritic diseases accompanied by swelling, stiffness and pain.
In the past, researchers have noted a link between some movement disorders and ME/CFS in young people. These include increased prevalence of ‘joint hypermobility syndrome’ (observed in 60% of patients versus 24% in healthy controls) and the presence of ‘Ehlers-Danlos syndrome’. For these reasons – and because postural abnormalities were sometimes observable in the young people attending their clinic – researchers at the University School of Medicine in Baltimore decided to examine ‘ranges of motion’ in the limbs and spine of young people with ME/CFS – with fascinating results.
The study included 48 adolescents and young adults with ME/CFS (Fukuda 1994 definition of CFS) and a healthy control group matched for sex and joint hypermobility. All were assessed for ranges of motion with tests commonly used in physical therapy practice. Test manoeuvres included ankle dorsiflexion (where the toes are stretched upwards), passive straight-leg raising, a seated slump, an upper-limb neurodynamic test (assessing tension, particularly of the median nerve), prone knee bend, and prone press-up – all designed to test how restricted participants were in particular bodily movements.
Compared with healthy controls, the young people with ME/CFS had significantly more abnormal results for range of motion on 6 of the 11 tests (left and right ankle dorsiflexion, left and right straight-leg raise, right upper-limb neurodynamic test, and abnormal prone press-up). In addition, they had a significantly greater number of body areas with impaired ranges of motion (5 areas in patients versus 2 in controls) at the start of stretch, and they were far more likely to have more than 3 areas where the range of motion was impaired. ME/CFS patients were also more likely to develop abnormal symptoms, e.g. fatigue, light-headedness, headache and nausea, after range of motion testing (44% of patients versus 0% of the controls). The researchers explored whether these observations could be explained by reductions in activity in the patients, but found that the number of range of movement limitations was unrelated to physical activity, as measured by questionnaire scores and rates of full-time school attendance.
The various physical examination manoeuvres used in this study to test range of motion add an ‘elongation strain’ to the nervous system and associated soft tissues (nerves change length or slide in their fascial beds in response to changes in movement). The authors speculate that ME/CFS patients – even at this young age – have a reduced compliance in their nervous system and connective tissue, and therefore an increased sensitivity to mechanical movement which limits their daily activities and contributes to symptoms. The next step is to tease out the mechanisms underlying these curious results.
Source: Rowe PC, et al. Impaired range of motion of limbs and spine in chronic fatigue syndrome. Journal of Pediatrics, 2014 Aug; 165(2): 360-6.
Pain characteristics of people with ME/CFS. An ME Research UK-funded study from Glasgow Caledonian University
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