Effect of hip joint angle at seat-off on hip joint contact force during sit-to-stand movement: a computer simulation study

Table 2 Comparison of the results of this study and of the previous studies

	This study	Previous studies
Joint moments (Nm/kg)
Minimum \|Hip extension moment\|
Peak hip extension moment	0.24*	0.24^a
Minimum \|Knee extension moment\|
Peak knee extension moment	0.47*	0.51^a
Minimum \|Ankle plantarflexion moment\|
Peak ankle plantarflexion moment	− 0.07*	0.02^a
All STS movements (718 variations) Sum of the peak hip and peak knee joint moments	1.51*	1.53^a
Normal STS movements (110 variations) Peak hip extension moment	0.52 (0.10)	0.71 (0.16)^b 0.62 (0.12)^c
Muscle forces (mean peak) (N/kg)
All STS movements (718 variations)
Gluteus maximus	19.0^†	5.6^d
Hamstrings	25.8^†	7.8^d
Quadriceps (vastus and rectus femoris)	37.6^†	36.5^d
Sum of the peak hip and peak knee extensor muscle forces	82.4^†	44.7^d
Normal STS movements (110 variations)
Gluteus maximus	16.9^‡	–
Hamstrings	7.0^‡	–
Quadriceps (vastus and rectus femoris)	32.4^‡	–
Sum of the peak hip and peak knee extensor muscle forces	56.3^‡	–
Joint contact force (N/kg)
Normal STS movements (110 variations)
Mean of the peak hip joint contact force	26.3^‡	19.2^e
		21.3^f
		19.6^g

^aYoshioka et al. [18]. The seat height was 0.4 m
^bInai et al. [43]. The seat height was 0.4 m
^cDoorenbosch et al. [16]. The seat height was unknown
^dYoshioka et al. [22]. The seat height was 0.4 m
^eBergmann et al. [25]. The seat height was 0.5 m. The value was calculated from {(1.81 BW + 2.08 BW + 1.82 BW + 2.20 BW + 1.90 BW)/5} × 9.8 m/s². BW: body weight
^fBergmann et al. [27]. The seat height was 0.45 m. The value was calculated from 1600 N/75 kg
^gStansfield et al. [26]. The seat height was unknown. The value was calculated from 2.0 BW × 9.8 m/s²
* The static components of the joint moments in this study were compared with the values reported by a previous study because the STS movements reported by Yoshioka et al. [18] were slow (4.12–10.98 s)
^†The mean value was calculated from the adopted STS movements of 878 variations because Yoshioka et al. [22] calculated their mean value from various STS movements of 160,086 variations
^‡The seat height in this study was 0.4 m. The mean value was calculated from the normal STS movements (i.e., the range of the hip flexion angle at seat-off was 93 ± 8°)

ISSN: 1475-925X