Muscle tone in diabetic polyneuropathy evaluated by the quantitative pendulum test.
OBJECTIVE
To quantify the muscle tone of upper limbs in patients with diabetic polyneuropathy (DPN).


METHODS
Case-control study. Quantitative upper-limb pendulum tests were conducted, and model analysis was performed.


METHODS
Outpatient clinic of a medical center.


METHODS
The experimental group consisted of patients with type 2 diabetes suffering from symptomatic but not disabling polyneuropathy. The diagnosis of polyneuropathy was based on symptoms, signs, and nerve conduction velocity (NCV) study. The control group consisted of age- and sex-matched normative subjects. In total, 181 subjects were recruited, including 128 controls and 53 DPN patients.


METHODS
Not applicable.


METHODS
Quantitative biomechanic parameters (number of swings, relaxation index, stiffness constant and damping coefficient) were formulated and the differences between groups were investigated.


RESULTS
The number of swings and stiffness constant showed no difference between groups. Relaxation index increased and damping coefficient decreased significantly in the DPN group.


CONCLUSIONS
Muscle tone, defined as passive resistance in the tested range, in DPN patients was shown to be decreased. The decrease was mainly due to a decrease in the velocity-dependent component. The decrease did not correlate with the decrease in NCV and could not be detected by the conventional manual pendulum test performed at the bedside.
Lin
Chou-Ching K
CC
Department of Neurology, University Hospital, Tainan, Taiwan. cx145@mail.ncku.edu.tw
Ju
Ming-Shaung
MS
Huang
Han-Wei
HW
D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology; D003929:Diabetic Neuropathies / Q000503:physiopathology*; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009129:Muscle Tonus / Q000502:physiology*; D009460:Neurologic Examination / Q000379:methods*; D025341:Principal Component Analysis; D034941:Upper Extremity / Q000503:physiopathology