Comparison of Cervical Vertebrae Rotations for PMHS and BioRID II in Rear Impacts

Figures & data

Fig. 1 Neck anatomy and dissection flow (cross section at C4).

Fig. 2 Cervical instrumentation: (a) custom instrumentation mount screwed on C4 and (b) instrumentation configuration with 3D CT reconstruction.

Fig. 3 Rear impact lab trial test: (a) C4 and C6 instrumentation and Steinmann pins with fiducials and (b) lateral view of test setup.

Fig. 4 General setup for the sled tests: (a) PMHS and (b) BioRID II.

Fig. 5 PMHS cervical instrumentation (PMHS08) for the sled tests: (a) fluoroscopic image and (b) 3D CT reconstruction.

Fig. 6 BioRID II cervical instrumentation (angular rate sensors shown in blue).

Fig. 7 Input pulse for the validation tests: (a) acceleration and (b) velocity.

Table 1 Quantitative comparison between kinematics obtained from instrumentation and video using NRMSD

	NRMSD (%)
Cervical spine kinematics	Subject 1	Subject 2
C3 x-displacement	0.4	0.7
C3 z-displacement	0.4	3.9
C3 y-rotation	2.5	7.6
C4 x-displacement	2.0	1.1
C4 z-displacement	2.3	1.1
C4 y-rotation	2.2	3.2
C5 x-displacement	1.4	0.5
C5 z-displacement	1.5	1.9
C5 y-rotation	2.6	3.2
C6 x-displacement	2.0	0.8
C6 z-displacement	0.9	2.6
C6 y-rotation	2.7	10.8
C7 x-displacement	2.4	0.3
C7 z-displacement	2.0	2.0
C7 y-rotation	14.4	4.6

Fig. 8 Rotation of the cervical vertebrae relative to the sled in the global y-axis (17 km/h test): (a) C2, (b) C3, (c) C4, (d) C5, (e) C6, and (f) C7.

Table 2 Biofidelity scores for the 17 km/h test

	SM	P	Biofidelity Score
C2	0.72	0.24	0.76
C3	1.25	0.05	1.25
C4	1.08	0.04	1.08
C5	1.26	0.06	1.26
C6	0.97	0.04	0.97
C7	0.85	0.06	0.85
Mean (SD)	1.02 (0.22)	0.08 (0.08)	1.03 (0.21)

Fig. 9 Rotation of the cervical vertebrae relative to the sled in the global y-axis (24 km/h test): (a) C2, (b) C3, (c) C4, (d) C5, (e) C6, and (f) C7.

Table 3 Biofidelity scores for the 24 km/h test

	SM	P	Biofidelity Score
C2	1.99	0.06	1.99
C3	3.00	0.04	3.00
C4	3.03	0.06	3.03
C5	2.41	0.05	2.41
C6	1.73	0.12	1.73
C7	1.45	0.04	1.45
Mean (SD)	2.27 (0.66)	0.06 (0.03)	2.27 (0.66)

Table 4 Peak relative intervertebral rotations (°)

	C2/C3	C3/C4	C4/C5	C5/C6	C6/C7
	mean	mean	mean	mean	mean
	(SD)	(SD)	(SD)	(SD)	(SD)
17 km/h
PMHS	−6.3  (4.1)	−5.4  (4.1)	−8.6  (5.5)	−6.4  (4.4)	−5.3  (3.4)
BioRID II	−1.8  (0.5)	−4.8  (0.6)	−4.4  (0.2)	−5.6  (1.2)	−4.3  (0.5)
P value	0.027	0.695	0.086	0.672	0.467
24 km/h
PMHS	−6.6  (3.0)	−6.9  (4.3)	−11.7  (6.0)	−8.7  (5.0)	−8.0  (4.2)
BioRID II	−1.2  (1.5)	−3.0  (1.0)	−3.7  (0.9)	−4.9  (0.9)	−5.4  (0.6)
P value	0.011	0.092	0.024	0.130	0.196

Table 5 Comparison of global vertebral rotations measured in the current study compared to studies in the literature. Rotations in the current study are reported as mean (SD)

	C2 (°)	C3 (°)	C4 (°)	C5 (°)	C6 (°)	C7 (°)
Deng 01	47.7	48.2	Not reported	48.4	43.6	Not reported
Deng 02	56.7	56.7	Not reported	49.9	34.5	Not reported
White 01	12.9	19.5	Not reported	40.6	39.7	Not reported
White 02	9.6	15	Not reported	25.7	18.3	Not reported
Current study (17 km/h)	29.2  (6.9)	32.5  (4.9)	34.8  (6.7)	38.2  (6.8)	40.9  (8.1)	42.6  (7.7)
Current study (24 km/h)	59.1  (7.0)	61.8  (6.3)	65.5  (8.2)	70.5  (10.5)	71.3  (12.7)	68.1  (12.9)

Table 6 Comparison of relative intervertebral rotations measured in the current study compared to studies in the literature. Rotations are reported as mean (SD)

	Test severity	Head restraint	C2/C3	C3/C4	C4/C5	C5/C6	C6/C7
Panjabi et al. (2005)	8 g	No	6.4  (4.0)	9.6  (6.3)	11.9  (6.2)	10.9  (7.3)	12.9  (8.3)
Ivancic et al. (2006)	8 g	No	7.2  (2.3)	6.1  (4.0)	15.4  (6.6)	10.6  (6.2)	14.5  (4.7)
Deng et al. (2000)	5 to 9.8 g and 5 to 16 km/h	No	−6.0  (2.0)	8.0  (3.0)	9.0  (4.0)	9.0  (6.0)	N/A
Deng et al. (2000)	5 to 9.8 g and 5 to 16 km/h	Yes	−5.0  (1.0)	−7.0  (5.0)	4.0  (1.0)	9.0  (4.0)	N/A
Current study (17 km/h)	8.5 g and 17 km/h	Yes	−6.3  (4.1)	−5.4  (4.1)	−8.6  (5.5)	−6.4  (4.4)	−5.3  (3.4)
Current study (24 km/h)	10.5 g and 24 km/h	Yes	−6.6  (3.0)	−6.9  (4.3)	−11.7  (6.0)	−8.7  (5.0)	−8.0  (4.2)

Panjabi , M M , Ito , S , Ivancic , P C and Rubin , W . 2005 . Evaluation of the intervertebral neck injury criterion using simulated rear impacts . J Biomech. , 38 : 1694 – 1701 .

 PubMed Web of Science ®Google Scholar

Ivancic , P C , Panjabi , M M , Tominaga , Y and Malcolmson , G F . 2006 . Predicting multiplanar cervical spine injury due to head-turned rear impacts using IV-NIC . Traffic Inj Prev. , 7 : 264 – 275 .

 PubMedGoogle Scholar

Deng , B , Begeman , P C , Yang , K H , Tashman , S and King , A I . 2000 . Kinematics of human cadaver cervical spine during low speed rear-end impacts . Stapp Car Crash J. , 44 : 171 – 188 .

 PubMedGoogle Scholar