Background
Methods
Subjects
Subject A | Subject B | Subject C | |
---|---|---|---|
Gender | Male | Male | Male |
Age (year) | 67 | 58 | 60 |
Length (cm) | 173 | 183 | 183 |
Mass (kg) | 84 | 80 | 65 |
Side affected | Right | Right | Right |
DLS-AFO use (years) | 5.9 | 5.7 | 1.6 |
Shoes | Low-cut off the shelf | High-cut orthopedic | Low-cut sports shoes |
Heel-sole difference shoe affected side (mm) | 15 | 23 | 0 |
Muscle strength, affected side (MRC scores) | |||
Hip flexors | 4+ | 5 | 5- |
Hip extensors | 5 | 5 | 5 |
Hip abductors | 5 | 5 | 4 |
Hip adductors | 5 | 5 | 5 |
Knee flexors | 4+ | 5 | 5 |
Knee extensors | 4+ | 5 | 5- |
Ankle dorsiflexors | 3 | 1 | 4 |
Ankle plantarflexors | 4 | 4 | 0 |
Passive joint range-of-motion# | |||
Hip flexion and extension | Normal | Normal | Normal |
Knee flexion and extension | Normal | Normal | Normal |
Ankle dorsiflexion (degrees)† | −10 | −10 | 40 |
Ankle plantarflexion (degrees)† | 60 | 45 | −10 |
Experimental AFOs
Procedures
DLS-AFO | SH-AFO | |
---|---|---|
k1 (most compliant) | 0.9 (0.1) | 0.05 (0.00) |
k2 (moderately compliant) | 1.4 (0.2) | 0.3 (0.04) |
k3 (medium stiff) | 2.7 (0.2) | 0.8 (0.1) |
k4 (moderately stiff) | 5.7 (0.2) | 1.4 (0.3) |
k5 (stiffest) | 7.2 (0.1) | 2.2 (0.4) |
Measurements
Stiffness properties of the experimental AFOs
Gait biomechanics
Walking speed and walking energy cost
Satisfaction
Data analysis
Stiffness properties
Gait biomechanics
Walking speed and waking energy cost
Statistics
Results
Experimental AFO stiffness properties
Gait biomechanics
Sagittal plane ankle angle
Shoes-only1 | DLS-k1 | DLS-k2 | DLS-k3 | DLS-k4 | DLS-k5 | Shoes-only2 | SH-k1 | SH-k2 | SH-k3 | SH-k4 | SH-k5 | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Speed (m•s−1) | ||||||||||||
Subject A | 1.11 (0.03) | 1.12 (0.04) | 1.14 (0.03) | 1.12 (0.04) | 1.15 (0.03) | 1.11 (0.02) | 1.07 (0.02) | 1.02 (0.03) | 0.93 (0.04) | 1.01 (0.04) | 1.02 (0.04) | 1.01 (0.02) |
Subject B | 1.27 (0.02) | 1.32 (0.02) | 1.35 (0.02) | 1.28 (0.03) | 1.31 (0.01) | 1.33 (0.02) | N/A | 1.20 (0.02) | 1.24 (0.05) | 1.13 (0.02) | 1.25 (0.02) | 1.20 (0.01) |
Subject C | 1.45 (0.03) | 1.50 (0.04) | 1.49 (0.05) | 1.50 (0.03) | 1.55 (0.05) | 1.55 (0.04) | 1.43 (0.03) | 1.34 (0.05) | 1.38 (0.04) | 1.33 (0.03) | 1.31 (0.03) | 1.27 (0.04) |
Maximum ankle angle stance (°)†; positive values are dorsiflexion, negative values plantarflexion | ||||||||||||
Subject A | 25.9 (1.1) | 18.8 (1.1) | 18.8 (0.6) | 13.8 (0.7) | 12.1 (0.7) | 10.4 (0.8) | 23.6 (0.7) | 15.7 (0.5) | 13.9 (1.3) | 14.7 (1.6) | 15.5 (0.9) | 13.5 (1.3) |
Subject B | 15.7 (1.0) | 14.1 (0.7) | 12.6 (0.7) | 10.9 (0.5) | 8.9 (0.3) | 9.0 (0.3) | N/A | 13.5 (0.8) | 12.2 (1.2) | 12.1 (1.1) | 9.4 (1.6) | 8.0 (0.4) |
Subject C | 16.6 (2.3) | 17.7 (1.2) | 22.1 (1.5) | 17.3 (0.9) | 14.4 (1.9) | 10.9 (1.5) | 12.3 (3.7) | 16.1 (2.8) | 17.0 (0.7) | 13.6 (0.6) | 15.1 (2.2) | 10.1 (1.0) |
Minimum ankle angle loading response (°)†; positive values are dorsiflexion, negative values plantarflexion | ||||||||||||
Subject A | −8.0 (1.0) | −11.9 (1.9) | −10.4 (1.5) | −10.0 (1.3) | −8.0 (0.8) | −8.1 (0.9) | −5.9 (1.2) | −9.7 (0.5) | −7.8 (0.9) | −9.8 (0.9) | −8.7 (0.5) | −9.7 (2.0) |
Subject B | −14.8 (1.1) | −5.9 (1.0) | −5.1 (0.9) | −4.1 (0.6) | −3.4 (0.2) | −3.5 (0.6) | N/A | −4.6 (0.9) | −7.3 (1.7) | −5.4 (0.1) | −6.4 (1.7) | −5.9 (0.5) |
Subject C | −15.9 (4.9) | −11.8 (1.9) | −7.5 (0.8) | −8.9 (1.4) | −6.4 (2.1) | −6.2 (0.8) | −20.1 (4.0) | −8.6 (3.8) | −4.9 (1.0) | −5.8 (1.5) | −4.6 (1.3) | −3.8 (1.4) |
Maximum internal ankle moment single stance (N•m•kg− 1); positive values are plantarflexion, negative values dorsiflexion | ||||||||||||
Subject A | 1.00 (0.04) | 1.05 (0.06) | 1.07 (0.05) | 1.11 (0.06) | 1.12 (0.02) | 1.08 (0.03) | 1.10 (0.04) | 1.14 (0.10) | 0.95 (0.07) | 1.16 (0.13) | 1.32 (0.10) | 1.33 (0.06) |
Subject B | 1.07 (0.04) | 1.25 (0.02) | 1.26 (0.03) | 1.26 (0.02) | 1.27 (0.02) | 1.26 (0.03) | N/A | 0.81 (0.04) | 0.85 (0.02) | 0.80 (0.002) | 0.82 (0.02) | 0.80 (0.02) |
Subject C | 0.91 (0.06) | 0.64 (0.03) | 0.76 (0.08) | 0.79 (0.10) | 0.90 (0.06) | 0.98 (0.06) | 0.75 (0.11) | 1.29 (0.05) | 1.19 (0.12) | 1.11 (0.09) | 1.10 (0.07) | 1.11 (0.06) |
Maximum ankle power single stance (Watt•kg−1); positive values are power generation, negative values absorption | ||||||||||||
Subject A | 2.6 (0.2) | 2.2 (0.2) | 2.1 (0.2) | 1.8 (0.3) | 1.4 (0.2) | 1.3 (0.1) | 2.3 (0.2) | 1.7 (0.2) | 1.1 (0.1) | 1.7 (0.2) | 1.9 (0.2) | 1.7 (0.2) |
Subject B | 1.5 (0.1) | 1.7 (0.1) | 1.7 (0.1) | 1.4 (0.1) | 1.3 (0.1) | 1.2 (0.1) | N/A | 1.2 (0.2) | 1.2 (0.1) | 1.1 (0.1) | 0.9 (0.1) | 0.8 (0.1) |
Subject C | 1.2 (0.2) | 1.5 (0.1) | 1.9 (0.2) | 1.9 (0.3) | 1.5 (0.2) | 1.4 (0.1) | 0.7 (0.3) | 0.6 (0.04) | 0.8 (0.2) | 0.6 (0.04) | 0.9 (0.1) | 0.8 (0.1) |
Minimum knee angle single stance (°); positive values are flexion, negative values extension | ||||||||||||
Subject A | 5.1 (0.9) | 6.1 (1.4) | 4.3 (1.1) | −0.4 (0.4) | 1.7 (0.4) | −0.2 (0.5) | 7.2 (0.8) | 8.1 (0.7) | 7.1 (0.9) | 7.3 (1.2) | 7.3 (1.5) | 5.1 (0.6) |
Subject B | 2.8 (0.5) | 4.0 (0.2) | 3.1 (0.6) | 4.4 (0.6) | 3.3 (0.2) | 3.2 (0.6) | N/A | −1.7 (0.5) | −1.5 (0.3) | −0.6 (2.7) | −2.7 (0.5) | −2.7 (0.3) |
Subject C | 16.8 (1.3) | 1.6 (0.8) | 1.4 (2.0) | −0.1 (0.7) | −1.6 (0.5) | −1.0 (4.0) | 16.4 (3.7) | 19.5 (7.2) | 12.6 (10.3) | 20.5 (3.8) | 19.8 (7.4) | 18.8 (6.8) |
Maximum knee angle early stance (°); positive values are flexion, negative values extension | ||||||||||||
Subject A | 17.6 (2.7) | 16.5 (1.0) | 17.6 (2.8) | 12.4 (1.2) | 16.5 (2.4) | 15.4 (1.1) | 16.3 (1.7) | 16.9 (1.7) | 16.1 (1.7) | 16.2 (0.7) | 19.0 (2.0) | 17.1 (0.3) |
Subject B | 25.8 (1.3) | 25.9 (1.5) | 28.5 (1.0) | 26.3 (1.8) | 28.6 (1.1) | 27.8 (1.3) | N/A | 19.9 (0.6) | 20.4 (1.6) | 22.8 (2.8) | 20.6 (1.5) | 20.8 (1.0) |
Subject C | 27.6 (1.5) | 23.7 (3.5) | 24.9 (4.6) | 26.3 (3.1) | 23.2 (1.7) | 26.1 (2.9) | 30.3 (4.2) | 27.5 (3.2) | 29.1 (2.2) | 33.0 (4.0) | 31.4 (3.5) | 30.6 (5.5) |
Minimum internal knee moment single stance (N•m•kg−1); positive values are extension, negative flexion | ||||||||||||
Subject A | 0.14 (0.03) | 0.14 (0.07) | 0.10 (0.08) | −0.09 (0.05) | −0.03 (0.04) | −0.07 (0.07) | 0.10 (0.03) | 0.07 (0.03) | 0.06 (0.07) | 0.04 (0.04) | 0.02 (0.05) | −0.07 (0.03) |
Subject B | −0.17 (0.05) | −0.20 (0.03) | −0.27 (0.03) | −0.17 (0.04) | −0.25 (0.01) | −0.22 (0.05) | N/A | −0.15 (0.03) | −0.17 (0.01) | −0.10 (0.19) | −0.22 (0.04) | −0.21 (0.03) |
Subject C | 0.33 (0.10) | 0.09 (0.03) | 0.06 (0.07) | −0.01 (0.04) | −0.12 (0.05) | −0.19 (0.14) | 0.34 (0.04) | 0.25 (0.09) | 0.09 (0.20) | 0.25 (0.07) | 0.27 (0.15) | 0.22 (0.16) |
Satisfaction about walking (NRS score)§ | ||||||||||||
Subject A | 4 | 5 | 5 | 7* | 2 | 6 | 3 | 5 | 5 | 5 | 4 | 5 |
Subject B | 4 | 6 | 6 | 6.5 | 7 | 7 | N/A | 5 | 8* | 6 | 6 | 7 |
Subject C | 5 | 4 | 3 | 7 | 6 | 8* | 6 | 2 | 3 | 4 | 4 | 6 |
Ankle power
Sagittal plane knee angle
Walking speed and walking energy vcost
Shoes-only1 | DLS-k1 | DLS-k3 | DLS-k5 | Shoes-only2 | SH-k1 | SH-k4 | SH-k5 | |
---|---|---|---|---|---|---|---|---|
Speed (m•s− 1) | ||||||||
Subject A | 1.08 | 1.14 (+6%) | 1.19 (+11%) | 1.13 (+5%) | 1.12 | 1.11 (−1%) | 1.12 (+0.4%) | 1.11 (−0.4%) |
Subject B | 1.26 | 1.25 (−1%) | 1.21 (−3%) | 1.28 (+2%) | N/A | 1.25 (−1%) | 1.21 (−4%) | 1.23 (−2%) |
Subject C | 1.44 | 1.45 (+0.3%) | 1.40 (−3%) | 1.48 (+2%) | 1.49 | 1.43 (−4%) | 1.46 (−2%) | 1.47 (−2%) |
Walking energy cost (J•kg−1•min−1) | ||||||||
Subject A | 4.22 | 4.16 (−2%) | 4.07 (−4%) | 4.03 (−5%) | 5.02 | 4.98 (−1%) | 4.49 (−11%) | 5.03 (+0.1%) |
Subject B | 4.71 | 4.33 (−8%) | 4.20 (−11%) | 4.82 (+2%) | N/A | 4.17 (−11%) | 3.86 (−18%) | 4.44 (−6%) |
Subject C | 4.73 | 5.00 (+6%) | 4.54 (−4%) | 4.36 (−8%) | 4.73 | 4.47 (−6%) | 4.48 (−5%) | 4.69 (−1%) |