The Shape&Roll prosthetic foot was used to examine the effect of roll-over shape arc length on the gait of 14 unilateral trans-tibial prosthesis users. Simple modifications to the prosthetic foot were used to alter the effective forefoot rocker length, leaving factors such as alignment, limb length, and heel and mid-foot characteristics unchanged. Shortening the roll-over shape arc length caused a significant reduction in the maximum external dorsiflexion moment on the prosthetic side at all walking speeds (p 5 0.001 for main effect of arc length), due to a reduction in forefoot leverage (moment arm) about the ankle. Roll-over shape arc length significantly affected the initial loading on the sound limb at normal and fast speeds (p ¼ 0.001 for the main effect of arc length), with participants experiencing larger first peaks of vertical ground reaction forces on their sound limbs when using the foot with the shortest effective forefoot rocker arc length. Additionally, the difference between step lengths on the sound and prosthetic limbs was larger with the shortest arc length condition, although this difference was not statistically significant (p ¼ 0.06 for main effect). It appears that prosthesis users may experience a dropoff effect at the end of single limb stance on prosthetic feet with short roll-over shape arc lengths, leading to increased loading and/or a shortened step on the contralateral limb.

Abstract-The performance and movement efficiency of prosthesis users while traversing a multisectional obstacle course (OC) were evaluated using a crossover design with random allocation of three prosthetic knee joints: the SNS (CaTech; Dayton, Ohio) the C-Leg (Otto Bock; Duderstadt, Germany), and the 3R60 (Otto Bock). Twelve users completed the OC twice with each joint, once without and once with a mental loading task (MLT). The performance was objectively assessed using time measurement from digital video recordings, and the Total Heart Beat Index was used to estimate movement efficiency. A 1 mo familiarization period was provided for each knee joint before data collection. It took longer to complete the OC with the 3R60 compared with either the SNS or the C-Leg. No significant time differences were found between the C-Leg and the SNS, but differences between the 3R60 and the SNS (slalom and rock sections) and between the 3R60 and the C-Leg (rock section) were observed. Within the simulated sand section, two participants fell with the C-Leg, one with the 3R60, and none with the SNS. Movement efficiency without MLT was similar between all joints, but with an MLT a significant decrease in movement efficiency was observed with the C-Leg. Previous experience using an SNS had no influence on the results.

Abstract-This review is an attempt to untangle the complexity of transtibial prosthetic socket fit, determine the most important characteristic for a successful fitting, and perhaps find some indication of whether a particular prosthetic socket type might be best for a given situation. Further, it is intended to provide directions for future research. We followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and used medical subject headings and standard key words to search for articles in relevant databases. No restrictions were made on study design or type of outcome measure. From the obtained search results (n = 1,863), 35 articles were included. The relevant data were entered into a predefined data form that incorporated the Downs and Black risk of bias assessment checklist. Results for the qualitative outcomes (n = 19 articles) are synthesized. Total surface bearing sockets lead to greater activity levels and satisfaction in active persons with amputation, those with a traumatic cause of amputation, and younger persons with amputation than patellar tendon bearing sockets. Evidence on vacuum-assisted suction and hydrostatic sockets is inadequate, and further studies are much needed. To improve the scientific basis for prescription, comparison of and correlation between mechanical properties of interface material, socket designs, user characteristics, and outcome measures should be conducted and reported in future studies.

The authors examined the roll-over shape alignment hypothesis, which states that prosthetic feet are aligned by matching their rollover shapes with an "ideal" shape. The "ideal" shape was considered to be the roll-over shape of the able-bodied foot-ankle system. An alignment algorithm and computational alignment system were developed to set transtibial alignments based on this hypothesis. Three prosthetic feet with considerably different roll-over shapes were either aligned using the alignment system or not aligned (i.e. used previous foot's alignment), and then were aligned by a team of prosthetists. No significant differences were found between roll-over shapes aligned by the computational alignment system and those based on standard clinical techniques (p = 0.944). Significant differences were found between the "no alignment" shapes and the prosthetist alignment shapes (p = 0.006), and between the "no alignment" shapes and the computational alignment system shapes (p = 0.024). The results of the experiment support the hypothesis that the goal of alignment is to match the prosthetic foot's roll-over shape, as closely as possible, with an "ideal" shape. The hypothesis is also supported by its ability to explain the results of previous studies. Using an "ideal" roll-over shape

The results show differences between healthy elderly and diabetic subjects during easy goal-oriented stopping tasks. Changes in gait termination parameters and the increased overshoots in particular document the pathology-related decline in postural stability.