Side-to-side confrontational strength-testing for weakness of the intrinsic muscles of the hand.

A prospective study of 217 patients was performed to determine the sensitivity and specificity of standard manual testing and of a new method, termed confrontational testing, for detecting weakness of the intrinsic muscles of the hand. Electrodiagnostic testing was used to identify the presence of any neurological disorder and to provide a control for the manual testing methods. Standard manual testing of the muscles innervated by the ulnar nerve revealed a sensitivity of 14 per cent, a specificity of 100 per cent, a predictive value of a positive result of 100 per cent, and a predictive value of a negative result of 57 per cent. Confrontational testing of the muscles innervated by the ulnar nerve revealed a sensitivity of 82 per cent, a specificity of 100 per cent, a predictive value of a positive result of 100 per cent, and a predictive value of a negative result of 87 per cent. Standard manual testing of the muscles innervated by the median nerve revealed a sensitivity of 6 per cent, a specificity of 100 per cent, a predictive value of a positive result of 100 per cent, and a predictive value of a negative result of 49 per cent. Confrontational testing of the muscles innervated by the median nerve revealed a sensitivity of 16 per cent, a specificity of 100 per cent, a predictive value of a positive result of 100 per cent, and a predictive value of a negative result of 52 per cent.