Table 4.
Angular velocities of upper arm elevation across 13 participants and three material transfer rates: slow (15 cycles/min), medium (30 cycles/min), and fast (30 cycles/min) that was maintained for a period of 1 min. Angular velocities were calculated using displacement measurements obtained from an optical motion capture system (OMC) an accelerometer (Accel), first-order complementary filter (Comp-1), a modified linear Kalman filter (Accel-KF), and an embedded Kalman filter (Em-KF).
| Velocity | OMC | Accel | Comp-1 | Comp-2 | Accel-KF | Em-KF |
|---|---|---|---|---|---|---|
|
| ||||||
| ‘Slow’ Transfer Rate | ||||||
| RMS error (°/s) | -REF- | 13.0(3.0) | 4.4(1.1)** | 9.9(0.8)** | 3.1(0.9)** | 2.8(1.0)** |
| Peak error (°/s) | -REF- | 42.7(11.4) | 14.1(4.4)** | 19.9(2.1)** | 9.7(3.4)** | 8.7(3.3)** |
| Mean (°/s) | 28.2(2.1) | 28.6(2.3) | 27.5(2.1) | 28.7(2.4) | 27.6(2.0) | 27.7(2.0) |
| 10th Percentile (°/s) | 2.6(1.1) | 4.0(1.3) | 2.9(1.3) | 4.4(0.7) | 2.7(1.2) | 2.6(1.2) |
| 50th Percentile (°/s) | 22.8(3.8) | 25.9(2.7) | 22.4(3.3) | 23.8(2.0) | 22.4(3.4) | 22.5(3.5) |
| 90th Percentile (°/s) | 61.3(8.7) | 56.6(7.0) | 59.4(8.4) | 59.6(7.7) | 59.9(8.4) | 60.1(8.5) |
| Percentile Range (90th – 10th)(°/s) | 58.7(9.5) | 52.6(7.7) | 56.5(9.3) | 55.2(7.8) | 57.2(9.3) | 57.4(9.4) |
| Time at low velocities (<5°/s)(%) | 19.5(6.4) | 13.2(3.7) | 18.1(6.2) | 11.5(1.9) | 19.0(6.3) | 19.6(6.3) |
| Time at high velocities (≥90°/s)(%) | 1.0(1.5) | 0.4(0.6) | 0.8(1.3) | 0.8(1.2) | 0.9(1.4) | 0.8(1.4) |
| ‘Medium’ Transfer Rate | ||||||
| RMS error (°/s) | -REF- | 39.8(10.9) | 10.3(2.4)** | 11.1(1.4)** | 5.9(1.4)** | 5.1(2.0)** |
| Peak error (°/s) | -REF- | 112.5(29.1) | 30.8(10.0)** | 25.6(7.9)** | 17.1(4.3)** | 15.3(7.7)** |
| Mean (°/s) | 56.0(5.3) | 49.7(5.9) | 54(5.4) | 54.3(5.3) | 54.8(5.3) | 54.7(5.2) |
| 10th Percentile (°/s) | 7.5(2.8) | 9.8(3.0) | 7.8(2.9) | 8.1(2.3) | 7.8(2.8) | 7.3(2.8) |
| 50th Percentile (°/s) | 52.6(6.1) | 49.3(7.2) | 50.0(5.5) | 49.9(6.2) | 51.3(5.8) | 51.4(6.0) |
| 90th Percentile (°/s) | 109.7(17.3) | 89.0(11.2) | 106.4(16.4) | 107.3(15.9) | 107.4(16.8) | 107.3(16.7) |
| Percentile Range (90th – 10th)(°/s) | 102.2(19.0) | 79.2(10.7) | 98.6(17.7) | 99.2(17.0) | 99.6(18.4) | 99.9(18.3) |
| Time at low velocities (<5°/s)(%) | 7.9(3.8) | 5.7(2.0) | 7.5(3.6) | 6.7(2.0) | 7.6(3.7) | 8.0(3.7) |
| Time at high velocities (≥90°/s)(%) | 21.7(8.5) | 9.8(6.0) | 19(8.6) | 19.5(8.1) | 20.0(8.7) | 20.2(8.7) |
| ‘Fast’ Transfer Rate | ||||||
| RMS error (°/s) | -REF- | 79.0(14.1) | 17.0(2.7)** | 13.8(3.7)** | 9.3(1.7)** | 7.3(3.9)** |
| Peak error (°/s) | -REF- | 206.5(41.1) | 46.2(8.4)** | 36.2(18.6)** | 25.2(5.8)** | 21.4(13.8)** |
| Mean (°/s) | 83.3(9.8) | 62.5(7.2) | 78.8(9.9) | 81.9(10.2) | 81.4(9.8) | 81.6(9.4) |
| 10th Percentile (°/s) | 14.5(3.1) | 11.4(2.5) | 15.2(4.6) | 13.5(4.0) | 15.1(4.0) | 15.0(3.6) |
| 50th Percentile (°/s) | 86.0(10.6) | 57.6(7.6) | 78.5(9.9) | 82.6(10.8) | 82.7(10.4) | 83.5(9.9) |
| 90th Percentile (°/s) | 146.5(20.1) | 118.5(16.6) | 141.9(20.6) | 148.5(19.7) | 144.4(20.2) | 144.0(19.7) |
| Percentile Range (90th – 10th)(°/s) | 131.9(20.2) | 107.1(16.2) | 126.7(19.7) | 135(18.9) | 129.3(19.9) | 128.9(19.8) |
| Time at low velocities (<5°/s)(%) | 3.6(0.9) | 4.6(1.3) | 3.5(1.0) | 4.0(1.3) | 3.6(1.0) | 3.5(1.0) |
| Time at high velocities (≥90/s)(%) | 46.7(6.1) | 24.1(6.9) | 41.3(7.6) | 44.9(6.1) | 44.6(6.5) | 45.3(6.1) |
*
Statistically-significant (p < 0.05) pair-wise tests between the Accel and the sensor fusion method.
**
Statistically-significant (p < 0.01) pair-wise tests between the Accel and the sensor fusion method.