Moving a patient with a potential spinal injury onto a spine board is a critical step in prehospital care. To ensure spinal immobilization during on-the-field management, various transfer techniques are employed. This article delves into a comparative analysis of three prominent spine board transfer methods: the 6-plus-person lift (6+ lift), the lift-and-slide (LS), and the traditional logroll (LR). Understanding the nuances of each technique is crucial for medical professionals to minimize spinal motion and prevent further injury during emergency situations.
The primary goal of this study is to objectively compare the spinal segment motion generated by the 6+ lift, LS, and LR techniques during spine board transfers. By evaluating the biomechanics of each method, we aim to determine which technique offers the most effective spinal immobilization, particularly in cases of cervical spine instability. This comparison is vital for optimizing prehospital protocols and ensuring the safety of patients with suspected spinal injuries.
Evaluating Spinal Motion in Different Transfer Techniques
This research employs a crossover study design to analyze and contrast the spinal motion produced by three distinct spine board transfer techniques: the 6-person lift, the lift-and-slide, and the logroll. The study meticulously measures and compares the degree of spinal movement at the C5-C6 segment, a critical area in cervical spine injuries, across these techniques. This comparison is essential for determining the safest and most effective method for transferring patients with potential spinal injuries onto a spine board.
Methodology: Cadaver Study and Motion Analysis
The study involved a team of eight experienced medical professionals performing each of the three transfer techniques on five fresh cadavers. Motion tracking technology was used to precisely measure three-dimensional angular and linear motions at the C5-C6 spinal segment. Measurements were taken under two conditions: first with intact spines, and then after surgically creating instability at the C5-C6 segment to simulate a spinal injury. This controlled experimental setup allowed for a direct comparison of how each technique impacts spinal motion in both stable and unstable conditions.
Figure 1: Demonstrating sensor placement for motion tracking on the anterior surface of vertebral bodies during the spine board transfer technique study.
Participants and Experimental Setup for Spine Transfer Comparison
Eight medical professionals, including physicians, certified athletic trainers, and hospital staff, participated in the study. Their experience in emergency medical care ranged from 5 to 32 years, ensuring a realistic execution of the transfer techniques. Five fresh cadavers with an average age of 86.2 years were used to simulate patient conditions. A controlled experimental lesion was created at the C5-C6 spinal level by a spine surgeon to mimic a globally unstable spinal segment, allowing for the assessment of spinal motion under compromised conditions. This rigorous setup ensured the reliability and validity of the comparative analysis of the 6-person lift versus logroll and lift-and-slide methods.
Data Collection and Variables in Spine Board Transfer Techniques
The study meticulously collected data on six dependent variables: axial rotation, flexion-extension, lateral flexion, anteroposterior displacement, distraction, and medial-lateral translation. These variables were measured at the C5-C6 spinal segment during each transfer technique. The independent variables were the transfer technique itself (6+ lift, LS, LR) and the spinal condition (stable vs. unstable). This detailed data collection allowed for a comprehensive statistical analysis to compare the effectiveness of each technique in minimizing spinal motion and ensuring spinal immobilization.
Statistical Analysis: Comparing Motion Across Techniques
A 2 × 3 analysis of variance with repeated measures was employed to statistically analyze the collected data. This method allowed researchers to determine the significant differences in spinal motion among the three transfer techniques and between stable and unstable spinal conditions. Post hoc pairwise comparisons with Bonferroni adjustments were used to pinpoint specific differences between techniques when necessary. The statistical significance level was set at p ≤ .05. This rigorous statistical approach ensured the validity of the findings and provided a clear comparison of the spinal motion generated by the 6-person lift, lift-and-slide, and logroll techniques.
Results: Motion Analysis of 6-Person Lift, Lift-and-Slide, and Logroll
The results of the study revealed significant differences in spinal motion among the three transfer techniques, particularly in unstable spinal conditions. Notably, the logroll technique generated significantly more axial rotation, lateral flexion, and medial-lateral translation compared to both the 6-person lift and the lift-and-slide techniques when performed on cadavers with a destabilized C5-C6 spinal segment. Flexion-extension and anteroposterior and distraction-compression linear motion did not show significant variation between the logroll and the other two lifting techniques.
Axial Rotation Comparison
Figure 2: Visual representation of angular motion in the transverse plane, comparing the 6-person lift, lift-and-slide, and logroll techniques under stable and unstable spinal conditions. Notice the significantly higher axial rotation with the logroll technique in unstable conditions.
The analysis of axial rotation data demonstrated a significant interaction between the lesion and the technique (P < .001). Post hoc tests showed that the logroll technique resulted in a significantly greater axial rotation (7.21° ± 0.73°) compared to both the 6-person lift (2.73° ± 0.33°, P = .008) and lift-and-slide (2.01° ± 0.37°, P = .001) techniques when performed on a destabilized C5-C6 segment. Furthermore, axial rotation with the logroll was significantly higher in unstable conditions compared to stable conditions (P = .002). This highlights the logroll’s potential to induce greater rotational stress on an unstable spine compared to the 6-person lift and lift-and-slide methods.
Flexion-Extension Motion Analysis
Figure 3: Sagittal plane angular motion comparison across the three spine board transfer techniques, illustrating flexion-extension motion under stable and unstable conditions. All techniques show increased motion in unstable conditions, but no significant difference between techniques.
In contrast to axial rotation, flexion-extension motion showed no significant differences among the three techniques or between stable and unstable conditions for any single technique. However, a main effect for lesion was observed (P = .007), indicating that spinal destabilization at C5-C6 generally led to greater flexion-extension motion, regardless of the transfer technique used. This suggests that while instability increases flexion-extension movement, the choice of transfer technique does not significantly alter this type of motion.
Lateral Flexion Comparison
Figure 4: Frontal plane angular motion comparison, demonstrating lateral flexion during 6-person lift, lift-and-slide, and logroll transfers in both stable and unstable spine scenarios. The logroll technique exhibits significantly higher lateral flexion in unstable conditions.
Lateral flexion analysis revealed a significant lesion-by-technique interaction (P < .001). Post hoc tests indicated that the logroll technique produced significantly more lateral flexion (7.50° ± 0.73°) compared to both the 6-person lift (2.35° ± 0.26°, P = .005) and lift-and-slide (2.58° ± 0.31°, P = .003) techniques in unstable spine conditions. Furthermore, all techniques showed significantly increased lateral flexion in unstable versus stable conditions (P < .05 for all). This further emphasizes that the logroll maneuver tends to induce greater lateral bending forces on a compromised cervical spine compared to the lifting techniques.
Anteroposterior Translation Analysis
Figure 5: Anteroposterior translation comparison across the three transfer methods under stable and unstable spinal conditions. Similar to flexion-extension, instability increases anteroposterior motion across all techniques, with no significant difference between techniques.
Analysis of anteroposterior translation showed a main effect for lesion (P = .016), indicating a notable increase in anteroposterior motion after spinal destabilization. However, no significant differences were found between the three transfer techniques. This suggests that while spinal instability increases forward and backward movement, the choice of transfer technique does not significantly mitigate or exacerbate this type of motion.
Distraction Motion (Axial Translation) Assessment
Figure 6: Distraction motion (axial translation) comparison during 6-person lift, lift-and-slide, and logroll techniques, highlighting motion under both stable and unstable spine conditions. Spinal instability leads to increased distraction motion for all techniques.
Statistical analysis of distraction data indicated a main effect for lesion (P = .03), with significantly greater distraction motion detected after creating the C5-C6 lesion. Again, no significant differences were observed between the transfer techniques themselves. This suggests that spinal instability increases the potential for axial separation at the injury site, but the transfer method does not significantly alter this.
Medial-Lateral Translation Comparison
Figure 7: Medial-lateral translation comparison across the three spine board transfer techniques in stable and unstable spinal conditions. The logroll technique results in significantly higher medial-lateral translation in unstable conditions.
Medial-lateral translation analysis showed a lesion-by-technique interaction (P < .001). Post hoc tests revealed that the logroll technique resulted in significantly greater medial-lateral translation (0.63 ± 0.06 cm) compared to both the 6-person lift (0.17 ± 0.02 cm, P = .003) and lift-and-slide (0.17 ± 0.02 cm, P = .004) techniques in unstable C5-C6 conditions. Furthermore, all techniques exhibited significantly increased medial-lateral translation in unstable versus stable conditions (P < .05 for all). This reinforces the finding that the logroll technique is associated with greater translational forces on an unstable spine compared to the lifting methods.
Discussion: Implications for Prehospital Spinal Immobilization
The findings of this study underscore that while some spinal motion is inevitable during spine board transfers, the choice of technique significantly impacts the type and magnitude of motion, especially in unstable spinal injuries. The logroll technique, while commonly used, consistently generated greater axial rotation, lateral flexion, and medial-lateral translation at the unstable C5-C6 segment compared to the 6-person lift and lift-and-slide techniques.
Logroll Limitations Compared to 6-Person Lift
The increased spinal motion observed with the logroll technique can be attributed to the more complex coordination required compared to the lifting techniques. During the logroll, the head must move along a curvilinear path, which may lead to perceptual errors and deviations in head-body alignment by the rescuer providing manual stabilization. Additionally, variations in body girth proportions during the logroll can induce slope changes in the thoracolumbar spine, potentially causing cervical spine deviations if not properly managed. These factors contribute to the logroll’s tendency to generate more rotational and translational forces on the cervical spine.
Advantages of 6-Person Lift and Lift-and-Slide Techniques
In contrast, the 6-person lift and lift-and-slide techniques involve lifting the patient directly, minimizing complex rotational movements. These techniques allow for a more controlled and linear movement of the head and torso as a unit, potentially reducing the risk of exacerbating spinal injuries, particularly in the presence of instability. The 6-person lift, advocated by the Inter-Association Task Force for Appropriate Care of the Spine-Injured Athlete, is particularly beneficial for heavier patients as it distributes the lifting workload among more rescuers.
Clinical Relevance and Future Directions
The results of this study align with previous research indicating that the logroll maneuver may generate more spinal motion, particularly in lateral flexion and axial rotation. The findings suggest that for patients with suspected cervical spine injuries, especially those with potential instability, the 6-person lift or lift-and-slide techniques may offer a safer alternative to the logroll maneuver by minimizing potentially harmful spinal movements.
Further research is warranted to investigate the combined use of the 6-person lift with a scoop stretcher, as suggested by the Inter-Association Task Force. Evaluating the effectiveness of scoop stretchers in limiting spinal motion during transfers could provide additional insights into optimizing prehospital spinal immobilization protocols. Additionally, future studies should consider the limitations of cadaver models, such as age-related tissue mobility changes and smaller body size compared to some patient populations, and explore the impact of rescuer experience and environmental factors on spinal motion during transfers in real-world settings.
Conclusion: Optimizing Spine Board Transfer Techniques for Spinal Immobilization
In conclusion, while all spine board transfer techniques inevitably induce some degree of spinal motion, the 6-person lift and lift-and-slide techniques appear to minimize motion across an unstable spinal segment more effectively than the logroll maneuver. Given the potential risks associated with increased spinal motion in patients with cervical spine injuries, particularly axial rotation and lateral flexion, emergency responders should consider adopting the 6-person lift or lift-and-slide techniques as preferred methods for spine board transfers, especially in situations where spinal instability is suspected. Further research and practical training are crucial to refine and implement these techniques to enhance patient safety in prehospital care.
Acknowledgments
This study was supported by a research grant from the National Operating Committee on Standards for Athletic Equipment, Overland Park, KS. The authors gratefully acknowledge David Block, Andrew Sawers, Jenn Badger, Zack Ruetz, and Chris Bell for their valuable assistance in data acquisition, and Joanne Clarke for her expert manuscript editing.
