Previously we have shown that alteration of sensory feedback in one digit results in grip (normal) force adjustments in several digits during a whole-hand grasping and lifting task, i.e., the adjustments are not digit specific (Reilmann et al. SFN Abstr. 1999). However, this may be attributed to the biomechanical constraints of the task (i.e., preventing the object from tilting). The present study further investigates whether fingertip forces in each digit can be exerted independently. Subjects performed a task that was free of the biomechanical constraints observed during grasping. Each digit of their right dominant hand was placed on a force transducer mounted on a moveable block. Subjects were instructed to prevent the blocks from sliding, while equal tangential pulling loads were applied with 50g weights at each digit. Additional pulling loads of 50g or 100g were then applied at individual digits. The mean grip force at each digit over a period of three seconds was compared before and after the additio...