Reduced performance in balance, walking and turning tasks is associated with increased neck tone in Parkinson's disease

Abstract

Rigidity or hypertonicity is a cardinal symptom of Parkinson's disease (PD). We hypothesized that hypertonicity of the body axis affects functional performance of tasks involving balance, walking and turning. The magnitude of axial postural tone in the neck, trunk and hip segments of 15 subjects with PD (both ON and OFF levodopa) and 15 control subjects was quantified during unsupported standing in an axial twisting device in our laboratory as resistance to torsional rotation. Subjects also performed six functional tests (walking in a figure of eight [Figure of Eight], Timed Up & Go, Berg Balance Scale, supine rolling task [rollover], Functional Reach, and standing 360-deg turn-in-place) in the ON and OFF state. Results showed that PD subjects had increased tone throughout the axis compared to control subjects (p=0.008) and that this increase was most prominent in the neck. In PD subjects, axial tone was related to functional performance, but most strongly for tone at the neck and accounted for an especially large portion of the variability in the performance of the Figure of Eight test (rOFF=0.68 and rON=0.74, p<0.05) and the Rollover test (rOFF=0.67and rON=0.55, p<0.05). Our results suggest that neck tone plays a significant role in functional mobility and that abnormally high postural tone may be an important contributor to balance and mobility disorders in individuals with PD.

Feldenkrais method and functionality in Parkinson’s disease: a randomized controlled clinical trial

“…Balance assessment was performed through functional activities which assess functional mobility: figure-of-eight walk test [16], timedup-and-go test (TUG) [17], rollover task, 360 degree turn-in-place task, functional-reach test, sitting-and-standing test [18], Berg balance scale (BBS) [19], hip flexion strength [20]. The results of these tests were compared to the results of the Feldenkrais group and of the control subjects.…”

“…A stopwatch was used to time (in seconds) the duration of the task. The task was performed twice, and the second trial duration was used for the analysis [18].…”

“…The subjects were instructed to turn in their preferred direction 360 degrees when they were ready to do so (self-initiated). Turn duration (in seconds) was measured from the first movement of the toe or heel off the floor until the last vertical contact of the foot (toe or heel) on the floor after a full 360-degree turn [18].…”

“…The subjects were asked to stay with their shoulders perpendicular to the measuring tape and both arms stretched out in a 90-degree shoulder flexion. They were then instructed to "reach forward as far as they could without losing balance or taking a step and the distance (in centimeters) they reached from the initial position was measured [18].…”

“…All participants performed three sets of three attempts. A total of nine replicates were recorded and the average was recorded subsequently [18].…”