Using Wearable Inertial Sensors to Estimate Kinematic Parameters and Variability in the Table Tennis Topspin Forehand Stroke
Table 5
Values of angles at joints in chosen events during topspin forehand of particular players (1-7)—means, standard deviations (SD), variations (V), and coefficients of variation (CV).
Variable
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
1
Mean (deg)
10.8
62.2
82.2
44.7
42.1
36.1
75.8
6.0
74.8
65.8
34.9
56.7
88.5
71.7
59.6
82.1
108.5
40.2
66.9
57.6
SD (deg)
11.6
11.9
33.9
16.6
13.2
32.7
6.2
43.2
3.4
6.9
15.8
26.1
39.9
30.8
27.6
24.2
19.6
74.3
10.9
9.3
V
135.1
141.2
1148.4
276.5
173.6
1067.2
38.6
1862.9
11.3
48.3
251.1
681.1
1593.4
947.4
759.6
586.3
383.7
5521.9
118.9
86.5
CV (%)
147.7
19.0
49.1
33.4
28.1
138.3
8.4
185.9
4.5
10.7
55.7
55.4
54.8
54.3
55.3
32.3
18.4
308.3
16.9
16.5
2
Mean (deg)
18.5
80.3
40.0
59.5
40.2
0.6
58.1
31.6
70.6
71.6
17.2
61.0
62.1
64.3
70.4
70.2
72.2
-8.4
50.5
61.8
SD (deg)
19.6
3.6
10.1
3.8
7.3
30.5
19.2
23.7
7.2
6.0
22.6
21.5
16.0
2.7
4.1
36.7
2.7
11.5
4.7
5.2
V
386.0
12.6
103.0
14.2
53.1
930.5
370.3
563.8
52.0
35.6
509.8
463.6
255.5
7.3
16.7
1344.6
7.4
132.5
21.9
27.0
CV (%)
144.6
4.4
23.1
6.4
17.7
931.5
35.04
88.0
10.4
8.4
181.5
41.5
24.1
4.2
5.8
48.5
3.8
131.3
9.0
8.4
3
Mean (deg)
17.2
68.8
33.9
38.1
50.0
11.5
67.5
40.4
47.9
57.7
-1.4
43.9
5.9
42.4
61.3
75.9
104.5
11.9
58.6
47.8
SD (deg)
3.5
7.6
8.1
4.5
4.7
2.4
2.4
8.3
3.6
5.1
3.4
22.2
4.4
21.2
29.5
2.3
8.9
6.6
5.7
7.7
V
12.2
57.1
65.5
20.0
22.2
5.6
5.7
68.9
12.6
26.4
11.6
493.9
19.6
450.0
871.6
5.2
78.9
43.9
32.6
58.5
CV (%)
20.8
11.1
24.2
11.3
9.3
19.2
3.5
19.1
7.6
8.9
147.0
66.4
78.0
66.6
65.7
3.0
8.3
48.5
9.8
15.7
4
Mean (deg)
14.6
67.3
-1.5
48.1
36.1
12.8
13.9
23.4
48.6
50.0
19.1
18.6
24.2
45.6
43.0
87.8
60.9
12.1
52.2
37.0
SD (deg)
6.0
17.7
2.7
10.0
6.4
7.6
7.0
3.0
16.7
6.7
6.0
7.2
6.8
17.3
12.9
3.9
3.5
6.1
16.8
4.9
V
35.4
311.6
7.1
100.6
40.4
57.8
49.4
8.9
277.9
45.2
36.4
52.3
45.7
297.8
165.7
15.2
12.0
37.6
281.6
23.9
CV (%)
41.8
27.8
214.5
22.5
16.6
59.3
47.9
13.0
37.8
13.4
32.7
40.5
30.4
44.9
31.0
4.4
5.7
52.6
36.8
12.7
5
Mean (deg)
21.1
61.8
79.5
46.1
40.4
6.0
48.3
30.3
49.8
55.2
10.3
62.3
54.9
49.5
50.5
107.1
113.8
-48.3
56.6
57.5
SD (deg)
3.5
4.9
6.3
3.9
7.6
3.8
6.2
6.3
3.2
5.1
4.6
4.4
4.8
3.1
6.5
2.4
4.4
7.7
4.3
4.7
V
12.0
23.6
40.1
15.6
57.8
14.5
38.8
40.3
10.3
25.8
21.2
19.7
23.1
9.7
42.8
5.9
19.0
59.6
18.2
22.6
CV (%)
16.9
7.9
7.9
8.5
20.0
60.7
13.1
21.1
6.5
9.2
46.1
7.1
8.8
6.3
12.7
2.3
3.8
15.2
7.5
8.18
6
Mean (deg)
0.8
60.6
102.7
39.3
38.7
22.3
29.0
26.8
45.5
44.1
27.2
35.3
88.9
48.9
52.9
135.2
71.8
-27.7
52.2
49.7
SD (deg)
2.6
3.4
8.7
5.0
3.5
2.9
4.0
3.5
3.1
3.7
2.5
5.2
6.2
5.1
3.4
37.6
4.7
20.2
6.4
4.6
V
6.5
11.8
75.4
25.4
12.2
8.2
16.4
12.1
9.8
13.7
6.3
26.9
38.3
25.8
11.6
1412.7
22.5
408.1
41.4
21.3
CV (%)
356.6
5.6
8.7
13.1
9.3
12.4
13.8
12.6
7.0
8.2
9.1
14.1
7.0
10.6
6.3
30.7
6.6
83.0
12.6
9.3
7
Mean (deg)
22.1
73.8
-6.5
26.7
33.2
-14.2
34.7
11.2
36.3
66.6
2.6
38.0
11.6
35.2
65.9
94.7
88.0
12.8
29.6
36.0
SD (deg)
9.7
4.6
5.2
6.2
4.6
4.6
5.6
5.8
1.1
3.1
3.4
5.9
4.8
1.4
2.6
4.6
5.0
6.9
3.4
3.7
V
94.4
20.8
27.5
38.4
20.7
21.3
30.9
33.2
1.2
9.8
11.4
34.3
23.2
1.8
6.6
21.0
25.3
47.5
11.4
14.0
CV (%)
43.7
6.7
76.3
22.9
13.8
35.1
15.1
48.4
3.0
4.7
121.2
14.7
42.0
3.9
3.9
4.8
5.8
57.3
11.3
10.4
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.
