Using Wearable Inertial Sensors to Estimate Kinematic Parameters and Variability in the Table Tennis Topspin Forehand Stroke

Table 4

Values of angles at joints in chosen events during topspin forehand in the entire group of players ()—means, standard deviations (SD), variations (V), and coefficients of variation (CV).

	Ready position					Backswing					Contact					Forward
	ShF	ElF	WrE	RKnF	LKnF	ShF	ElF	WrE	RKnF	LKnF	ShF	ElF	WrE	RKnF	LKnF	ShF	ElF	WrE	RKnF	LKnF
Mean (deg)	13.2	66.1	44.7	43.3	41.4	8.7	47.6	25.4	51.9	58.0	26.4	43.7	47.7	47.6	52.7	90.8	87.0	-3.0	51.1	49.7
SD (deg)	9.2	6.6	41.5	10.6	5.3	8.6	20.9	11.8	14.3	8.9	11.8	15.3	39.3	12.7	9.3	18.2	21.5	25.2	10.8	10.1
V	84.3	43.9	1727.8	111.5	28.1	74.9	435.0	139.3	203.6	78.7	139.1	232.8	1542.5	162.4	87.3	330.9	464.1	636.2	117.2	102.7
CV (%)	69.6	10.0	92.4	24.4	12.8	99.2	43.8	46.5	27.5	15.3	44.6	34.9	82.3	26.8	17.7	20.0	24.7	851.0	21.2	20.4

ShF: shoulder flexion; ElF: elbow flexion; WrE: wrist extension; RKnF: right knee flexion; LKnF: left knee flexion. Average variability. Small variability. Not marked CV: high and very high variability.