ABSTRACT: This study compared the general activity during 1 week and detailed activity during a 24-hr period of 48 established unilateral transtibial prostheses users. Activity was measured by instrumenting their prescribed prosthesis, which they have been using for a minimum of 6 months, with the ActivPAL™ activity monitor. Half (n = 24) were fitted with a prosthesis with total surface bearing (TSB) pressure-cast sockets (“hands-off” group), and the other half (n = 24) had been wearing prostheses with hand-cast patellar tendon-bearing (PTB) sockets (“hands-on” group). As a prerequisite, the long-term reliability of the ActivPAL activity monitor was assessed, and it was found to exhibit a high level of consistency between devices (intraclass correlation coefficient [ICC] of 0.997 during the 24-hr period). The monitors were used to examine the activity levels of the two groups of transtibial prostheses users wearing their own prosthesis. The results indicated that both subject groups were active throughout the day, walking a mean of more than 8000 steps. No statistically significant difference in daily stepping activity was seen between the two groups (p = 0.173). Despite differences in prosthetic socket design, the daily activity profiles of both subject groups were similar.