Introduction
Methods
Study subjects
Measurements
Gait analysis and data processing
Gait assessment
3-min walking test
Validity
Statistical analysis
Results
Study subjects
Patients (n = 14) | Controls (n = 70) | Difference (p-value) | |||
---|---|---|---|---|---|
median | range | median | range | ||
Gender (% female) | 43 | 43 | |||
Age (years) | 11 | (5–16) | 11 | (5–16) | 0.05 |
Height (cm) | 147 | (101–168) | 154 | (109–187) | 0.11 |
Weight (kg) | 38.2 | (14.9–57.0) | 41.2 | (17.7–108.5) | 0.63 |
BMI (kg/m2) | 17.8 | (13.9–21.2) | 18 | (12.8–33.3) | 0.75 |
Leg length (mean) | 75 | (46–85) | 82 | (53–100) | 0.02 |
3-min walking test (distance, m) | 215 | (131–283) | 235 | (180–370) | 0.03 |
Cooperation first test (1–5 scale) | 5 | (2–5) | 5 | (3–5) | 0.03 |
Cooperation second test (1–5 scale) | 5 | (3–5) | 5 | (3–5) | 0.05 |
Cooperation third test (1–5 scale) | 5 | (3–5) | 5 | (3–5) | 0.04 |
Cooperation forth test (1–5 scale) | 5 | (2–5) | 5 | (3–5) | 0.05 |
Cooperation fifth test (1–5 scale) | 5 | (2–5) | 5 | (4–5) | <0.001 |
Cooperation 3MWT (1–5 scale) | 5 | (2–5) | 5 | (4–5) | 0.06 |
Gender | Age | Gene | Mutation | Heteroplasmy (%) | Mitochondrial syndrome | Myopathy, encephalopathy or encephalomyopathy? | Wheelchair for long distances? | Psychomotor retardation? | Ataxia | Exercise intolerance | Muscle weakness | Cardiomyopathy | Hearing loss | Vision loss | Contracture of achilles tendon | Scoliosis | Cooperative |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
M | 5 |
TAZ
| c.788_794del | Barth | M | + | + | + | + | + | |||||||
M | 9 | mt deletion | m.08649_16084del 7435bp | 30 (U) | CPEO | M | + | + | |||||||||
M | 13 |
MT-TL1
| m.3243A>G | 96 (U) | M | + | + | + | |||||||||
F | 14 |
RARS
| c.442A>G; c.1519G>A | E | + | + | + | + | |||||||||
M | 10 |
MT-TL1
| m.3243A>G | 61 (U) | M | + | + | ||||||||||
M | 10 |
MT-TL1
| m.3243A>G | 81 (U) | M | + | + | + | |||||||||
F | 12 |
MT-TL1
| m.3243A>G | 93 (U) | EM | + | + | + | + | + | |||||||
F | 13 |
MT-TL1
| m.3243A>G | 71 (U) | M | + | + | ||||||||||
M | 8 |
MT-ATP6
| m.09185t>C | Leigh | EM | + | + | + | + | + | |||||||
M | 15 |
MTFMT
| c.626C>T; c.766C>T | Leigh | EM | + | + | ||||||||||
M | 16 |
MT-TL1
| m.3243A>G | 87 (U) | MELAS | EM | + | + | + | + | + | + | |||||
F | 10 |
MT-TI
| m.04300A>G | 100 (M) | MICM | M | + | + | + | + | + | ||||||
F | 5 |
NDUFS7
| c.364A>G | Leigh-like | E | + | |||||||||||
F | 15 |
AGK
| c1131+5G>A | Sengers | M | + | + | + | + | + | + |
Feasibility
Gait characteristics
Pre-exercise protocol (test 2) | Post-exercise protocol (test 3) | Difference (p-value) | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Patients (n = 14) | Controls (n = 70) | Patients (n = 14) | Controls (n = 70) | Patients versus controls | Test 2 vs 3 | ||||||||
median | range | median | range | median | range | median | range | Test 2 | Test 3 | Patients | Controls | ||
Velocity | (cm/s) | 103 | (75–149) | 124 | (83–157) | 108 | (75–157) | 124 | (63–163) | 0.05/0.25# | 0.20/0.32# | 0.09 | 0.26 |
Cadence | (step/min) | 120 | (100–157) | 120 | (97–167) | 120 | (102–198) | 120 | (95–165) | 0.70/0.49# | 0.47 | 0.09 | 0.70/0.49# |
Step length | (cm) | 52 | (36–70) | 62 | (33–78) | 54 | (36–73) | 63 | (30–80) | 0.006/0.14# | 0.007/0.10# | 0.11 |
0.03
|
Step length variability | (cm) | 3.7 | (2.0–6.9) | 3.1 | (1.6–7.9) | 3.8 | (2.3–8.0) | 3.2 | (1.2–10.6) | 0.29 |
0.02
| 0.59 | 0.47 |
Step length asymmetry | (cm) | 1.6 | (0.2–3.1) | 1.5 | (0.04–4.7) | 1.2 | (0.22–4.9) | 1,0 | (0.03–4.1) | 0.92 | 0.86 | 0.29 | 0.34 |
Step time | (ms) | 499 | (382–599) | 498 | (358–619) | 502 | (303–589) | 499 | (363–630) | 0.54 | 0.7 | 0.33 | 0.15 |
Step time variability | (ms) | 30 | (14–94) | 25 | (14–67) | 29 | (17–80) | 24 | (12–86) | 0.36 | 0.06 | 1.00 | 0.34 |
Step time asymmetry | (ms) | 5,0 | (<0.01–24) | 9,0 | (<0.01–51) | 13 | (<0.01–33) | 8.5 | (<0.01–42) | 0.13 | 0.65 |
0.008
| 0.81 |
Step width | (cm) | 9.8 | (5.1–22.1) | 8.8 | (3.6–14.7) | 9.8 | (4.0–19.1) | 8.4 | (3.9–14.5) | 0.18 | 0.06 | 0.11 |
<0.001
|
Step width variability | (cm) | 3.3 | (2.3–5.2) | 2.5 | (1.1–5.1) | 3.5 | (2.4–6.5) | 2.7 | (1.4–6.5) | 0.07 |
0.05
| 0.29 | 0.06 |
Reliability
Pre-exercise protocol (test 1 versus 2) | |||||||
---|---|---|---|---|---|---|---|
Patients (n = 14) | Controls (n = 70) | Cooperative patients (n = 11) | |||||
ICC | 95%CI | ICC | 95%CI | ICC | 95%CI | ||
Velocity | (cm/s) |
0.900
| (0.721–0.967) | 0.775 | (0.662–0.854) |
0.941
| (0.807–0.984) |
Cadence | (step/min) | 0.583 | (0.132–0.841) |
0.908
| (0.857–0.942) |
0.940
| (0.788–0.984) |
Step length | (cm) |
0.971
| (0.911–0.990) |
0.960
| (0.937–0.975) |
0.946
| (0.813–0.985) |
Step length variability | (cm) | 0.625 | (0.145–0.863) | 0.336 | (0.109–0.529) | 0.547 | (−0.082–0.857) |
Step length asymmetry | (cm) | 0.162 | (−0.432–0.634) | 0.426 | (0.213–0.600) | 0.211 | (−0.438–0.712) |
Step time | (ms) | 0.580 | (0.127–0.893) |
0.934
| (0.895–0.958) |
0.917
| (0.724–0.977) |
Step time variability | (ms) | 0.726 | (0.357–0.902) | 0.394 | (0.177–0.575) | 0.739 | (0.265–0.923) |
Step time asymmetry | (ms) | 0.543 | (0.0.63–0.824) | 0.252 | (0.018–0.460) | 0.471 | (−0.084–0.818) |
Step width | (cm) |
0.980
| (0.914–0.994) |
0.851
| (0.771–0.905) |
0.969
| (0.811–0.993) |
Step width variability | (cm) | 0.618 | (0.135–0.860) | 0.463 | (0.256–0.629) | 0.529 | (−0.101–0.850) |
Post-exercise protocol (test 3 versus 4) | |||||||
Velocity | (cm/s) |
0.835
| (0.568–0.944) |
0.809
| (0.710–0.877) |
0.984
| (0.934–0.996) |
Cadence | (step/min) | 0.209 | (−0.327–0.650) |
0.935
| (0.897–0.959) |
0.970
| (0.893–0.992) |
Step length | (cm) |
0.972
| (0.916–0.991) |
0.950
| (0.959–0.984) |
0.957
| (0.855–0.988) |
Step length variability | (cm) | 0.699 | (0.277–0.893) | 0.223 | (−0.14–0.435) | 0.698 | (0.180–0.910) |
Step length asymmetry | (cm) | 0.747 | (0.372–0.912) | 0.543 | (0.356–0.689) | 0.718 | (0.233–0.916) |
Step time | (ms) | 0.403 | (−0.114–0.756) |
0.946
| (0.915–0.966) |
0.953
| (0.839–0.987) |
Step time variability | (ms) |
0.870
| (0.645–0.956) | 0.500 | (0.301–0.658) |
0.841
| (0.508–0.955) |
Step time asymmetry | (ms) | 0.411 | (−0.062–0.753) | 0.430 | (0.222–0.601) | 0.361 | (−0.128–0.755) |
Step width | (cm) |
0.974
| (0.917–0.992) |
0.893
| (0.833–0.932) |
0.960
| (0.863–0.989) |
Step width variability | (cm) | 0.742 | (0.315–0.913) | 0.451 | (0.241–0.620) | 0.709 | (0.103–0.919) |
Recovery protocol (test 2 versus 5) | |||||||
Velocity | (cm/s) |
0.977
| (0.930–0.992) | 0.766 | (0.601–0.860) |
0.973
| (0.904–0.993) |
Cadence | (step/min) |
0.918
| (0.701–0.975) |
0.880
| (0.717–0.940) |
0.960
| (0.863–0.989) |
Step length | (cm) |
0.945
| (0.837–0.982) |
0.939
| (0.903–0.961) |
0.913
| (0.719–0.976) |
Step length variability | (cm) | 0.765 | (0.416–0.918) | 0.277 | (0.044–0.481) | 0.722 | (0.238–0.917) |
Step length asymmetry | (cm) | 0.165 | (−0.370–0.624) | 0.212 | (−0.016–0.422) | 0.082 | (−0.536–0.633) |
Step time | (ms) |
0.933
| (0.735–0.980) |
0.888
| (0.731–0.944) |
0.938
| (0.785–0.983) |
Step time variability | (ms) |
0.855
| (0.618–0.951) | 0.389 | (0.173–0.570) |
0.889
| (0.658–0.968) |
Step time asymmetry | (ms) | 0.380 | (−0.125–0.741) | 0.519 | (0.323–0.671) | 0.263 | (−0.325–0.722) |
Step width | (cm) |
0.969
| (0.904–0.990) |
0.782
| (0.672–0.859) |
0.954
| (0.847–0.987) |
Step width variability | (cm) | 0.608 | (0.122–0.857) | 0.348 | (0.125–0.537) | 0.626 | (0.081–0.884) |