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Table 1 Maximal muscle forces and peak joint reaction forces (JRF) in different ranges of motion for the natural shoulder model, the reverse shoulder prosthesis model and the dual-bearing shoulder prosthesis model

From: Effect of two types of shoulder prosthesis on the muscle forces using a generic multibody model for different arm motions

 

Natural shoulder (NS)

Reverse shoulder prosthesis (RSP)

Dual-bearing shoulder prosthesis (DBSP)

 

Force (N)

Activation

Force (N)

% Change from NS

Activation

Force (N)

% Change from NS

Activation

ABD

        

Anterior deltoid

136.3

0.27

121.7

− 11

0.24

116.5

− 15

0.23

Middle deltoid

292.4

0.25

299.4

 + 2

0.25

396.8

 + 36

0.33

Posterior deltoid

330

0.20

156.5

− 53

0.10

107.9

− 67

0.07

Supraspinatus

56.1

0.09

–

–

–

–

–

–

Infraspinatus

95.4

0.07

152.7

 + 60

0.11

130.2

 + 36

0.09

Teres minor

36.6

0.07

118

 + 222

0.24

68.9

 + 88

0.14

Subscapularis

213.6

0.15

205

− 4

0.14

58.6

− 73

0.04

JRF

1054.0

 

1142.2

 + 8

 

957.5

− 9

 

SCP

        

Anterior deltoid

126.7

0.25

143.3

13

0.28

146.4

16

0.29

Middle deltoid

227.1

0.19

265.5

17

0.22

370.4

63

0.31

Posterior deltoid

281.8

0.17

195.2

− 31

0.12

137.2

− 51

0.08

Supraspinatus

53.4

0.09

–

–

–

–

–

–

Infraspinatus

220.9

0.15

255.9

16

0.18

259.5

17

0.18

Teres minor

38.6

0.08

139.5

261

0.28

80.7

109

0.16

Subscapularis

40.2

0.03

19.8

− 51

0.01

14.7

− 63

0.01

JRF

1031.6

 

1176.8

14

 

1095

6

 

IR

        

Anterior deltoid

110.2

0.22

113.9

3

0.23

130.4

18

0.26

Middle deltoid

187.4

0.16

277.2

48

0.23

307.4

64

0.26

Posterior deltoid

19.2

0.01

30.9

61

0.02

43.1

124

0.03

Supraspinatus

50.2

0.08

–

–

–

–

–

–

Infraspinatus

374.8

0.26

338

− 10

0.24

392.3

5

0.27

Teres minor

180.3

0.36

162.5

− 10

0.33

117.6

− 35

0.24

Subscapularis

110.7

0.08

19.9

− 82

0.01

14.5

− 87

0.01

JRF

827.6

 

935.9

13

 

946.3

14

 

ER

        

Anterior deltoid

122.7

0.24

112.4

− 8

0.22

133.7

9

0.26

Middle deltoid

157.8

0.13

292.4

85

0.25

309.9

96

0.26

Posterior deltoid

17.9

0.01

39

118

0.02

44.4

148

0.03

Supraspinatus

49.6

0.08

–

–

–

–

–

–

Infraspinatus

369.3

0.26

329.3

− 11

0.23

392.4

6

0.27

Teres minor

171.3

0.34

151.6

− 12

0.31

108.4

− 37

0.22

Subscapularis

111.6

0.08

16.2

− 85

0.01

14.6

− 87

0.01

JRF

779.5

 

935

20

 

982.5

26

 
  1. ABD abduction, SCP scaption (SCP), IR internal rotation, ER external rotation