The paper grip test for screening on intrinsic muscle paralysis in the foot of leprosy patients.

Plantar intrinsic foot muscles provide structure to the foot during walking and thus regulate mechanical foot sole stresses. When paralyzed, for instance in leprosy patients with neuropathy of the distal part of the tibial nerve, there is a high prevalence of plantar ulceration and deformities, especially when muscle weakness goes together with loss of foot sole sensibility. These patients should get immediate care involving education, special footwear and reconstructive surgery before further foot impairment and deformity becomes manifest. Thus far, in leprosy patients little attention is paid to screening of plantar intrinsic muscles activity. This can be done with a new simple and non-invasive method, the Paper Grip Test (PGT). There are two variants for detecting intrinsic muscle weakness of the foot, PGT1 for the great toe and PGT2 for the combined lesser toes. In this study, 517 leprosy patients and 170 healthy volunteers were investigated with the PGT. Sensibility of the foot sole was tested by means of a 10 gram monofilament. Specificity to the PGT1 is found to be about 95.3% which is considered good for physical diagnostic tests. PGT2 is less specific than PGT1. Individual muscle power and understanding of the patient seems to influence the outcome of the test to a certain extent. Sensitivity can only be calculated when the diagnosis is confirmed by electromyography. Especially patients with anesthetic feet, females, older patients and patients with PN-, BB- or LL-types of leprosy appeared to have a higher prevalence of intrinsic foot muscle weakness. All results were analyzed by means of the bivariate Pearson correlation-analysis and proved to be statistically significant (p = < 0.05). It is concluded that the PGT1, more than the PGT2, is a useful screening test on the function of plantar intrinsic foot muscles in leprosy patients in hospitals and during fieldwork in developing countries.