Article

Approximately 60% of stroke survivors experience hand dysfunction
limiting execution of daily activities. Several methods have been proposed to
objectively quantify fingers' joints range of motion (ROM), while few studies
exist about multi-finger coordination during hand movements. The present work
analysed this aspect, by providing a complete characterization of spatial and
temporal aspects of hand movement, through the mathematical modelling of
multi-joint finger motion in healthy subjects and stroke patients. METHODS: Hand
opening and closing movements were examined in 12 healthy volunteers and 14
hemiplegic stroke survivors by means of optoelectronic kinematic analysis. The
flexion/extension angles of metacarpophalangeal (MCPJ) and proximal
interphalangeal joints (IPJ) of all fingers were computed and mathematically
characterized by a four-parameter hyperbolic tangent function. Accuracy of the
selected model was analysed by means of coefficient of determination (R2) and
root mean square error (RMSE). Test-retest reliability was quantified by
intraclass correlation coefficient (ICC) and test-retest errors. Comparison
between performances of healthy controls and stroke subjects were performed by
analysing possible differences in parameters describing angular and temporal
aspects of hand kinematics and inter-joint, inter-digit coordination. RESULTS:
The angular profiles of hand opening and closing were accurately characterized by
the selected model, both in healthy controls and in stroke subjects (R2 > 0.973,
RMSE < 2.0 degrees ). Test-retest reliability was found to be excellent, with ICC
> 0.75 and remarking errors comparable to those obtained with other methods.
Comparison with healthy controls revealed that hemiparetic hand movement was
impaired not only in joints ROM but also in the temporal aspects of motion: peak
velocities were significantly decreased, inter-digit coordination was reduced of
more than 50% and inter-joint coordination patterns were highly disrupted. In
particular, the stereotypical proximal-to-distal opening sequence (reversed
during hand closing) found in healthy subjects, was altered in stroke subjects
who showed abnormally high delay between IPJ and MCPJ movement or reversed moving
sequences. CONCLUSIONS: The proposed method has proven to be a promising tool for
a complete objective characterization of spatial and temporal aspects of hand
movement in stroke, providing further information for a more targeted planning of
the rehabilitation treatment to each specific patient and for a quantitative
assessment of therapy's outcome.

Langue : ANGLAIS