[Validation of the motor capacities scale: a specific evaluation of manual abilities in tetraplegics who undergo functional surgery of the upper limbs].

OBJECTIVE

Metrological investigation to develop a motor capacities scale (MCS) specifically designed for tetraplegics who undergo a functional surgery of upper limbs.

METHODS

From diverse sources-review of literature, discussion with patients and therapists-, 328 daily life activities were compiled. Eighty of them were identified as motor capacities and correspond to basic and functional tasks performed by tetraplegics independently of contextual and environmental factors. Because of the absence of a reference test, a process of validation was required. In the preliminary study, patients and occupational therapists were asked to criticize the pertinence of the study. In the pilot study, patients were assessed on the basis of a protocol. Feasibility of the evaluation was also studied. The intermediate study was focused on the interrater reproducibility. The prefinal study aimed at assessing construct validity. In the final study, the external structure of the scale and responsiveness to change provided by functional surgery were analyzed.

RESULTS

The preliminary and pilot studies revealed the good acceptability of the scale by both the patients and the therapists. Face and content validity were enhanced by the multidisciplinary and multicenter approach. Global reproducibility was found to be excellent (intraclass correlation coefficient = 0.99). MCS was correlated with the Sollerman test, the functional independence measure (FIM), the ASIA motor score, dynamometric scores of Jamar and Preston. No correlation was found with the interval since the onset of the tetraplegia, the educational level and the age at the time of the evaluation. A factorial analysis was performed in 125 patients (146 observations) and revealed one main dimension that appears to reflect manual abilities. Responsiveness to change was important regarding the short time following surgery. The final version of the MCS comprises 31 items classified in six functional categories: transfers, positioning on a Bobath's couch, positioning in a wheelchair, locomotion, motor capacities of spatial exploration and motor capacities for grasping and gripping.

CONCLUSION

The MCS displays satisfactory metrological properties: a good apparent and content validity, an excellent reproducibility and a good construct validity. The data showed that sensitivity to change was good enough to consider the MCS as a valid means of assessment of the effectiveness of upper limb functional surgery in tetraplegics.