Analysis of patients with bodyboarding injuries transported by physician-staffed emergency helicopter

Abstract

Context:

There have been no reports that have studied the characteristics specific to bodyboard injuries.

Aims:

To clarify characteristics to bodyboard injuries.

Settings and Design:

A retrospective medical chart review.

Materials and Methods:

A medical chart review was retrospectively performed for all patients with spinal cord injuries transported via physician-staffed emergency helicopters between January 2009 and October 2013. The subjects were divided into two groups based on whether they had a spinal cord injury induced by bodyboarding (Bodyboard group, n = 14) or not (Control group, n = 14).

Statistical Analysis Used:

Using a χ²-test, Mann-Whitney U-test and non-paired Student's t-test.

Results:

All but one of the subjects had spinal canal stenosis. The age of the patients in the Bodyboard group was younger than that of the Control group. The ratio of males and Glasgow Coma Scale of the Bodyboard group were higher than those on the Control group. The spinal cord injury induced by bodyboarding typically occurred after impacts of the head or face with the sea bottom while the subject was being buffeted by the waves. The severity of the spinal cord injury in the Bodyboard group was lower than that in the Control group.

Conclusion:

Bodyboarding tended to induce spinal cord injuries after the head or face collided with the sea bottom, and was more common in middle-aged males during the summer season, and was associated with a favorable outcome.

INTRODUCTION

In March 2004, an emergency medical system including physician-staffed emergency helicopters (HEMS) was initiated in Eastern Shizuoka prefecture, located near Tokyo. The helicopter parks at our hospital, which has an emergency and critical care center, and is the only hospital that can treat patients with acute phase spinal cord injuries on Izu Peninsula. During the summer, as well as during vacations and on weekends, a lot of tourists visit Izu Peninsula, and patients with many kinds of diseases or injuries are transported to our hospital by the HEMS. Among them, we experienced several patients with spinal cord injury induced by bodyboarding during the summer season. In a previous study, surfing or water sports-related cervical spinal injuries, including those sustained while bodyboarding, were investigated together.[1,2] There have been two previously published case reports of cervical spinal injuries induced by bodyboarding;[3,4] however, there have been no reports that have studied the characteristics specific to bodyboard injuries, so we performed a retrospective investigation of our cases.

MATERIALS AND METHODS

This retrospective study protocol was approved by the review board of Juntendo Shizuoka Hospital, and the examinations were conducted according to the standards of good clinical practice and the Declaration of Helsinki.

A medical chart review was retrospectively performed for all patients with spinal cord injuries transported via physician-staffed emergency helicopters between January 2009 and October 2013. The exclusion criteria included spinal cord injury induced by marine sports other than bodyboarding. The subjects were divided into two groups based on whether they had a spinal cord injury induced by bodyboarding (Bodyboard group) or not (Control group). The patients’ age, sex, occurrence during the summer season (July and August), mechanism of injury, vital signs at the scene (Glasgow Coma Scale, blood pressure and heart rate), Frankel classification, manual muscle test on the upper and lower extremities, radiological findings, level of spinal cord injury, duration of admission and survival rate were analyzed. The neurological state 6 months after the spinal cord injury was determined by performing telephone interviews or medical chart review when the subjects were still admitted after 6 months in our hospital.

The statistical analyses were performed using a χ²-test, Mann-Whitney U-test and non-paired Student's t-test. A P-value < 0.05 was considered to indicate a statistically significant difference. All data are presented as the means ± standard error.

RESULTS

During the investigated period, there were 39 cases of spinal cord injury. Among them, 11 cases which were induced by marine sports other than bodyboarding [nine cases of subjects being buffeted by the waves (4 cases where the subjects were just swimming, two cases where they were swimming using a swimming ring, two cases where the subjects were surfing and one case where the subjects was using a floating air mat), one case where the subject was diving and one case where the subject was thrown into the sea] were excluded. The remaining 28 cases were defined as the study subjects. There were 14 subjects in the Bodyboard group and 14 in the Control group. There have been no other reports concerning other types of injury induced by bodyboarding during the investigated period.

The results of the comparison between the two groups are shown in Table 1. There were no significant differences concerning the systolic blood pressure, heart rate at the scene, radiological findings and survival rate between the two groups. All but one of the subjects had spinal canal stenosis. The exceptional case who had no abnormal radiological findings was a 5-year-old male who was given a diagnosis of spinal cord injury without any radiological abnormality. The age of the patients in the Bodyboard group was younger than that of the Control group. The ratio of males and Glasgow Coma Scale of the Bodyboard group were higher than those on the Control group. The spinal cord injury induced by bodyboarding typically occurred after impacts of the head or face with the sea bottom while the subject was being buffeted by the waves. The frequency of an initial Frankel Grade A status in the Bodyboard group was lower than that observed in the Control group. The rate of improvement in the Bodyboard group was significantly greater than that of the Control group. The duration of admission in the Bodyboard group was significantly shorter than that observed in the Control group.

Table 1.

Results of the comparison between the Bodyboard and Control groups

DISCUSSION

This study demonstrated that bodyboarding tended to induce spinal cord injury mainly due to collisions of the head or face with the sea floor. The mechanism of injury induced by such collisions was thought to be hyperextension associated with pre-existing spinal canal stenosis, and this usually caused central cord syndrome. This mechanism was similar to a bodysurfing injury,[5,6] which is uncommon in Japan.

In comparison with the spinal cord injury induced by traffic accidents or falls, the spinal cord injury induced by bodyboarding occurred more often during the summer season, in younger males and had tendency to be of mild severity. In addition, among the various marine sports, bodyboarding was the leading cause of spinal cord injury in subjects transported by the HEMS in Izu peninsula. Concerning the surfing injuries described in previous reports, most were caused by striking the surfboard, followed by striking the seabed.[7,8,9] Most injuries included soft tissue injuries, followed by dislocation and fractures.[7,8,9] The body parts most frequently injured were the lower limb, followed by the head/face.[7,8,9] Spinal injuries rarely occur when the surfer's head strikes the seafloor.[10] Dimmick et al., reported the radiological findings of injuries induced by surfing treated at a tertiary spinal injury center.[10] Fracture and/or dislocation of the cervical spine was the most common finding, observed in nine patients, followed by fracture of the thoracic spine in two patients and fracture of the lumbar spine in one patient. Four patients sustained contusions to the cervical cord. Two cases of cord contusion were secondary to focal intervertebral disc prolapse; the other two patients with cord contusions had associated cervical spine fractures. In the cases of acute spinal injury, the mechanism of injury was falling from the board and striking the seafloor. Concerning skimboarding injuries, such injuries usually occur following the sudden deceleration of the board as it transitions from the water to land or falls into shallow water.[11] The prevalence of lower extremity fractures following upper extremity fractures is much higher than that observed in surfing.[11] Furthermore, concerning kite-surfing injuries, the most common mechanism of injury is direct trauma caused by colliding into objects such as stones or boats lying on the beach due to the loss of control of the kite on or close to the beach as a result of technical mistakes by the surfer, the use of an oversized kite or poor wind conditions.[12,13] Kite-surfing injuries can be severe and/or fatal. The most commonly injured sites are the foot and ankle, followed by the skull, chest and knee. In comparison with that observed in other types of marine sports, bodyboard injuries have different characteristics concerning the mechanism, site and severity of the injury.

The leading cause of spinal cord injury in this study was bodyboarding. Surfing is a surface water sport that involves riding waves on a surfboard. Body surfing is a sport that involves riding a wave without the assistance of any buoyant device, such as a surfboard or bodyboard. Body surfing also tends to lead to incomplete spinal cord injury in predominantly middle-aged males with a pre-existing narrow spinal canal after hyperextension of the head and neck due to the surfers having been caught up in turbulent wave action and driven into the sea bottom. In comparison with surfing or body surfing, bodyboarders ride on a board, with the boarder's head sticking out while they hold the board with both hands, so that the center of gravity of the boarder is lowered downward to the toes by the buoyancy of the board. As a result, the bodyboarder can easily be rotated by the turbulent wave action, which increases the chance of them impacting the sea bottom with their head or face, with a delay of defense using both hands to prevent the impact to the head or face because the subject is holding onto the board. In addition, bodyboarding involves a skill called “el rollos”, which is characterized by intensively tweaking the board with the momentum of the wave and then swinging it back. Such motion might increase the risk of hitting the head or face, leading to the occurrence of a spinal cord injury.

The major reason for the etiology concerning the bodyboard injuries is that younger males are much more likely to bodyboard during the summer season than are older people.[1,2,3,4,14] In comparison with the Control group, the low-energy accidents occurring during bodyboarding resulted in a milder grade of spinal cord injury. In cases with severe spinal cord injury with cervical and upper thoracic spinal injury, there tends to be neurogenic shock, which leads to hypotension with bradycardia, so that the vital signs at the scene in the Control group were associated with a lower heart rate than was noted in the Bodyboard group.[15] Excluding the symptoms of spinal shock, the severity of the spinal cord injury during the first check positively correlates with the recovery of neurogenic dysfunction.[16] Accordingly, the mild grade severity of the spinal cord injury in the Bodyboard group resulted in these patients obtaining favorable outcomes.

CONCLUSIONS

Among the various marine sports, the leading cause of spinal cord injury in Izu peninsula was bodyboarding. Bodyboarding tended to induce spinal cord injuries after the head or face collided with the sea bottom, and was more common in middle-aged males during the summer season, and was associated with a more favorable outcome in comparison with the spinal cord injuries induced by traffic accidents or falls.