Use of the Microsoft Kinect system to characterize balance ability during balance training

Figures & data

Figure 1 Experimental configuration used to generate and characterize the motion of the participants.

Table 1 Summary of the center of body mass (COM) and joint angles measured using the Kinect system and the 3D infrared camera system

Balance index	Axis	Depth sensor-based Kinect system	Infrared camera-based motion capture system	P-value	γ
COM alteration (mm)	x (medial–lateral)	135.07±22.06	118.82±21.22	0.22	0.61
	y (anterior–posterior)	98.02±18.27	118.81±42.46	0.3	0.59
	z (cranial–caudal)	67.49±32.4	43.84±12.46	0.13	0.66
Hip joint alteration (°)	x (medial–lateral)	20.43±4.76	17.14±3.89	0.22	0.73
	y (anterior–posterior)	14.14±7.53	13.52±2.31	0.85	0.23
	z (cranial–caudal)	37.48±30.67	18.25±7.53	0.17	0.14
Knee joint alteration (°)	x (medial–lateral)	31.09±22.23	25.82±5.46	0.58	0.42
	y (anterior–posterior)	16.81±8.88	12.34±7.53	0.37	0.18
	z (cranial–caudal)	34.61±26.61	12.63±6.13	0.08	0.32

Note: Data are presented as mean ± standard deviation.

Figure 2 Changes in the center of body mass (COM).

Notes: (A) In the medial–lateral direction (x-axis). (B) In the anterior–posterior direction (y-axis). (C) In the cranial–caudal direction (z-axis). (D) A 3D representation of the alteration of COM.

Figure 3 Changes in the joint angles of the hip.

Notes: (A) During flexion–extension in the medial–lateral direction (x-axis). (B) During abduction–adduction in the anterior–posterior direction (y-axis). (C) During internal-external rotation in the cranial–caudal direction (z-axis).

Figure 4 Changes in the joint angle of the knee.

Notes: (A) During flexion–extension in the medial–lateral direction (x-axis). (B) During abduction–adduction in the anterior–posterior direction (y-axis). (C) Internal–external rotation in the cranial–caudal direction (z-axis).