TABLE 3.

Number of Participants Who Adjusted the Digit Forces in Response to Local Friction (N = 12)

	Digit
Digit force	Thumb	Index	Middle	Ring	Little
Normal	10	1	4	2	2
Tangential	7	4	5	2	5

Note. For each participant, a paired sign test was used over the 16 pairs of trials in which a digit was at high-friction contact (HFC) or low-riction contact (LFC), whereas the other four digits were in contact with same surfaces. If normal forces were larger at LFC than at HFC or if tangential forces were smaller at LFC than at HFC in a statistically significant number of paired tasks (more than 12), then the participant was considered to have used local friction adjustments.