Table 1 Summary of the main validation studies analyzing motion capture accuracy of the Kinect (v1 and v2) and of wearable IMUs
Refs. | Sensor(s) | Participants | Exercises | Parameters | Applications | Performance |
|---|---|---|---|---|---|---|
[49] | Kinect v1 | 1H | 6 primary movements | Joints positions, bone lengths | At-home elderly rehabilitation | RMSE \(< 10cm\) |
[50] | Kinect v1 | 20H | Reaching, standing balance | Joints positions | Postural control | ICC \(< 0.16\) CV \(<11.6\%\) |
[51] | Kinect v1 | 48H, 2 sessions | 4 primary movements | Joints angles | Funct. assessment | RMSE \(<9\%\) |
[52] | Kinect v1 | 10H + 9PD | 12 primary and functional movements | Joints positions and angles, timings | PD assessment | LoA \(<10\%\) ICC \(>0.9\) |
[53] | Kinect v1 | 20H | Standing sway | Marker positions | Exergaming | SDev \(<30\%\) |
[54] | Kinect v1 | 15H | Squat | Lower limb joints angles | Kinect evaluation | RMSE \(<5^\circ\) ICC \(>0.9\) |
[36] | Kinect v2 | 30H, 2 sessions | Standing balance | Trunk and pelvis angles | Balance and postural control | r \(>0.75\) ICC \(>0.7\) |
[42] | Kinect v2 | 30H, 2 sessions | Walking | Lower limbs joints angles | Gait analysis | \(0.4<\) r \(< 0.75\) |
[39] | Kinect v2 | 20H | 5 primary shoulder movements | Upper limbs joints angles | Clinic and home rehabilitation | RMSE = \(3.9^\circ\) |
[43] | Kinect v2 | 20H | Walking | Stance and step time, step length, time, velocity | Gait analysis | LoA \(<11\%\) ICC \(>0.9\) |
[41] | Kinect v2 | 30H | Standing and sitting exercises | Upper body joint positions | Rehabilitation | RMSE \(<5\%\) r \(>0.9\) |
[55] | 4 IMU (custom) on thighs, shanks | 3H | Walking | Hip and knee joint angles | Gait analysis | RMSE \(<8.7^\circ\) r \(>0.7\) |
[6] | 2 IMU (Xsens MTx) on pelvis, thigh | 20H | Walking | Hip joint angle | Gait analysis | LoA \(= 1.6^\circ\) |
[56] | 8 IMU (Xsens MTx) on thorax, lower back, thighs, shanks, feet | 9H (children) | Static postures | Hip and knee joint angles | Knee amputees and cerebral palsy | RMSE \(=1.8^\circ\) |
[57] | 6 IMU (not specified) on pelvis, thigh, shank | 9H + 1INJ | Running and outdoor training routines | Activity classification, hip and knee joints angles | Athlete training, injury prevention | 98% |
[58] | 3 IMU (Shimmer) on thigh, shank, foot | 58REH | Primary movements | Exercise recognition | Clinic and home rehabilitation | 83% |
[8] | 5 IMU (Riablo) on trunk, thigh, shank | 22H, 2 sessions | 4 knee exercises | Hip and knee joint angles | Clinic and home rehabilitation | RMSE \(=3.1^\circ\) |
[59] | 2 IMU (Opal) on lower back, upper arm | 6H | ADL routines, walking | Trunk and upper limb joints angles | IMU evaluation | RMSE \(<5.5^\circ\) |
[60] | 6 IMU (Xsens MTx) on thigh, shank, foot | 1AMP | Walking | Knee angle | Gait analysis | RMSE \(<3^\circ\) |
[61] | 7 IMU (Opal) on trunk, upper arm, forearm, hand | 8H | 2 swimming styles | Upper limb joints angles | swimming analysis | RMSE \(<7^\circ\) |
[62] | 3 IMU (Opal) on waist, thigh, shank, 1 resistive strip | 14H | Sit-to-stand, walking | Exercise timings, stride length | Clinic and home rehabilitation | r \(>0.7\) ICC \(>0.95\) |
[63] | 17 IMU (Synertial) full body | 20H | 5m timed up and go | Full body joints | Clinic evaluation | RMSE \(<13.6^\circ\) |
[64] | 2 IMU (APDM) thigh and shank | 18REH | Knee ROM, walking | Knee angle | Clinic rehabilitation | – |
[9] | 17 IMU (Xsens MVN) full body | 12H | Functional movements, work actions | Full body model | Occupational biomechanics | RMSE \(<5^\circ\) |
[65] | 3 IMU (I2M MT) on pelvis, trunk, upper arm | 6H lab + 10H workplace | Work actions | Trunk orientation, shoulder joint angles | Occupational biomechanics | RMSE \(<12.1^\circ\) |
[47] | Kinect v1, Kinect v2 | 20H (v1) + 20H (v2) | 15 static poses | Joints positions | Posture evaluation | RMSE(v1) \(=76mm\) RMSE(v2) \(=87mm\) |
[48] | Kinect v1, Kinect v2 | 10H, 3 camera angles | Sitting and standing postures | Joints positions | Motion capture | RMSE \(<100mm\) |
[33] | Kinect v1, Kinect v2 | 13H | ROM and static stretching exercises | Joints positions | Rehabilitation | RMSE \(=15mm\)(wrist) RMSE \(<10mm\)(other) |
[66] | Kinect v1 + 2IMU (InertiaCube3) on upper limb | 1H | Hand-to-mouth | Upper limb position | Motion capture | – |
[67] | Kinect v1 + 1 x-IMU | 1H | Knee flexion/extension | Knee angle | Motion capture | RMSE \(<14.2^\circ\) |
[68] | Kinect v1 Vs Kinovea (MBS) Vs Hillcrest (IMU) | 2H | Walking | Hip and knee angles | Gait rehabilitation | RMSE \(=3^\circ\) (IMU) RMSE \(=10^\circ\) (Kin.) |