Except for hip-hiking, variables were analyzed using repeated measures analysis of variance with limb (x2; intact, prosthetic) and prosthetic foot-type (x2; hyA-F, habF) as repeated factors.
Mean MTC increased for both limbs when using the hyA-F compared with habF (2.17 vs 1.90 cm) and was also greater on the intact compared with prosthetic limb (2.20 vs 1.91 cm).
The foot angle was reduced (indicating a slightly less toes-down foot angle) on the prosthetic compared with intact side (-17.7[degrees] vs -20.8[degrees]), and this angle was reduced for both limbs when using the hyA-F compared with habF; the interaction indicated that the reduction in foot angle was only significant on the prosthetic side (reduction: intact limb 1.0[degrees]; prosthetic limb 4.8[degrees]).
There was a trend for the knee to be more flexed at contralateral MTC when using the hyA-F compared with habF (11.0[degrees] and 9.7[degrees]; p = 0.09).
Hip-hiking was unaffected by foot type (hyA-F: 7.1 mm, habF: 5.5 mm; p = 0.37), as was hip-hiking variability (hyAF: 23.2 mm, habF: 20.2 mm; p = 0.39).
As expected, mean walking speed was greater when using the hyA-F compared with when using the habF (p < 0.001) (Table 1), which is why we investigated a priori the relationship between walking speed and each outcome measure.
Mean MTC significantly increased for both the prosthetic and intact limbs when using the hyA-F compared with habF. This suggests that people with amputation might have a reduced risk of tripping when walking with a hyA-F.
Why variability in MTC was increased on the prosthetic limb when using the hyA-F compared with habF is unclear.
Abbreviations: COM = center of mass, EPSRC = Engineering and Physical Sciences Research Council, habF = habitual prosthetic foot, hyA-F = foot with a hydraulic ankle attachment, MTC = minimum toe clearance, SD = standard deviation.