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Table 3 Data on 3D gait biomechanics and satisfaction

From: Stiffness modification of two ankle-foot orthosis types to optimize gait in individuals with non-spastic calf muscle weakness – a proof-of-concept study

  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
  1. Subject A: calf muscle strength MRC 4, subject B: calf muscle strength MRC 4, subject C: calf muscle strength MRC 0. Gait biomechanics data are expressed as mean (SD). Shoes-only1 is performed at the DLS-AFO testing day, Shoes-only2 is performed at the SH-AFO testing day (subject B had all AFO conditions tested at one day, therefore only one shoes-only condition was performed)
  2. Loading response: 1–10% gait cycle, early stance: 1–20% gait cycle, †: plantar and dorsiflexion angles are relative to the ankle angle at initial contact, §: satisfaction about walking in general when walking on shoes-only and with different AFO stiffness scored on a numeric rating scale (NRS) with 10 as highest satisfaction, *: quotes about the most satisfying condition: subject A: “was just sufficient for my remaining muscle force; it supports, but obstructs not too much”. Subject B: “it gives support, but not annoyingly. I like the design of the SH-AFO, the ankle feels not completely blocked in an angle of 90 degrees”. Subject C about all SH-AFO conditions and DLS-AFO-k1 and k2: “too compliant, does hardly anything”. About DLS-AFO-k3 he said: “support starts to increase”, and about the DLS-AFO-k5 “giving the best support”
  3. Abbreviations: DLS: dorsal-leaf-spring ankle-foot-orthosis, SH: spring-hinged ankle-foot-orthosis, k: stiffness (from most compliant (k1) to most stiff (k5)), N/A: not applicable