Yes, a young child jumping on a trampoline can cause unnecessary damaging compression or spinal trauma. Trampoline-related injuries (TRIs) are a significant concern, particularly in children, due to the forces involved during jumping and the potential for falls.
Several studies have documented the types and mechanisms of injuries associated with trampoline use. For instance, spinal injuries, including cervical and thoracic fractures, have been reported in children using trampolines.[1-3] The American Academy of Pediatrics has highlighted the risks associated with trampoline use, recommending against their recreational use due to the high incidence of injuries.[1]
Biomechanical studies have shown that the forces exerted on a child's body during trampoline use, especially when multiple users are involved, can be substantial. These forces can lead to significant orthopedic injuries, including fractures and ligamentous injuries.[4] Additionally, the compressive axial loading and varus shearing forces during trampoline use can increase the risk of physeal injuries, which are particularly concerning in growing children.[5]
In summary, the evidence indicates that trampoline use by young children can indeed result in damaging compression and spinal trauma, and caution is advised to prevent such injuries.

References

1.
Too Many Pediatric Trampoline Injuries.

Furnival RA, Street KA, Schunk JE.

Pediatrics. 1999;103(5):e57. doi:10.1542/peds.103.5.e57.

Background: Recent reports note a dramatic increase in the number of pediatric trampoline injuries (PTI) during the past several years. In 1996, the US Consumer Product Safety Commission estimates that 83 000 patients received treatment for trampoline injuries in US hospital emergency departments (EDs), and that approximately 75% of these patients were <15 years of age. We sought to review our experience with PTI since our previous report (Pediatrics 1992;89:849), and to determine if the American Academy of Pediatrics' current (Pediatrics 1981;67:438) safety recommendations are adequate.

Methods: Retrospective medical record review of all PTI patients presenting to the pediatric ED from November 1990 through November 1997.

Results: A total of 727 PTI patients were included; medical records were unavailable for 3 patients. The annual number of PTI nearly tripled during the study period, from 51 in 1991 to a peak of 148 in 1996. PTI patients were 53% female, with a median age of 7 years; 37% were <6 years of age. Privately owned trampolines accounted for 99% of PTI. Most injuries (66%) occurred on the trampoline, 28% resulted from falls off, and 4% from imaginative mechanisms. One hundred eleven patients (15%) suffered severe injury (1990 Abbreviated Injury Scale value >/=3), usually of an extremity (89 out of 111). Fractures occurred in 324 patients (45%). Spinal injuries were common (12%), including 7 patients with cervical or thoracic fractures, and 1 with C7 paraplegia. Fractures were more frequently associated with falls off the trampoline, whereas spinal injuries more frequently occurred on the trampoline. Eighty patients (11%) required prehospital medical transport to our ED, 584 (80%) had ED radiographs, and 382 (53%) required pediatric surgical subspecialty involvement. Seventeen percent of PTI patients (125 out of 727) were admitted to the hospital, including 9 to the pediatric intensive care unit; 99 (14%) required one or more operations. Mean hospital stay was 2 days (range, 1-63 days); 24 stays (19%) were for >/=3 days. We estimate that the hospital charges for the acute medical care of PTI study patients at our institution totaled approximately $700 000.

Conclusions: PTI are dramatically increasing in number, and result in considerable childhood morbidity. Most PTI occur on privately owned trampolines. Few, if any, safety recommendations for the trampoline are followed. We support recommendations for a ban on the recreational, school, and competitive pediatric use of trampolines.

2.
Trampoline Injuries.

Nysted M, Drogset JO.

British Journal of Sports Medicine. 2006;40(12):984-7. doi:10.1136/bjsm.2006.029009.

Leading Journal

Objective: To describe the mechanism, location and types of injury for all patients treated for trampoline-associated injuries at St Olav's University Hospital, Trondheim, Norway, from March 2001to October 2004.

Materials And Methods: Patients were identified from a National Injury Surveillance System. All patients were asked to complete a standard questionnaire at their first visit at the hospital. Most data were recorded prospectively, but data on the mechanism of injury, the number of participants on the trampoline at the time of injury, adult supervision and whether the activity occurred at school or in another organised setting were collected retrospectively.

Results: A total of 556 patients, 56% male and 44% female, were included. The mean age of patients was 11 (range 1-62) years. 77% of the injuries occurred on the body of the trampoline, including falls on to the mat, collisions with another jumper, falls on to the frame or the springs, and performing a somersault, whereas 22% of the people fell off the trampoline. In 74% of the cases, more than two people were on the trampoline, with as many as nine trampolinists noted at the time of injury. For children <11 years, 22% had adult supervision when the injury occurred. The most common types of injuries were fractures (36%) and injury to ligaments (36%). Injuries to the extremities predominated (79%), and the lower extremities were the most commonly injured part of the body (44%). A ligament injury in the ankle was the most often reported diagnosis (20%), followed by an overstretching of ligaments in the neck (8%) and a fracture of the elbow (7%). Regarding cervical injuries, two patients had cervical fractures and one patient had an atlantoaxial subluxation. Three patients with fractures in the elbow region reported an ulnar nerve neuropathy. 13% of the patients were hospitalised for a mean of 2.2 days.

Conclusion: Trampolining can cause serious injuries, especially in the neck and elbow areas of young children. The use of a trampoline is a high-risk activity. However, a ban is not supported. The importance of having safety guidelines for the use of trampolines is emphasised.

3.
Trampoline Injuries of the Cervical Spine.

Brown PG, Lee M.

Pediatric Neurosurgery. 2000;32(4):170-5. doi:10.1159/000028929.

Trampolines were responsible for over 6,500 pediatric cervical spine injuries in 1998. This represents a five-fold increase in just 10 years. While most have been minor, paraplegia, quadriplegia and death are all reported. We present 2 cases of trampoline-related cervical spine injury and review the relevant literature. Additionally, we examine the efforts made to reduce the incidence of trampoline injuries, and discuss why these have failed. We conclude that safety guidelines and warnings are inadequate. In addition, we support recommendations for a ban on the use of trampolines by children.

4.
Trampoline-Related Injuries in Children: A Preliminary Biomechanical Model of Multiple Users.

Menelaws S, Bogacz AR, Drew T, Paterson BC.

Emergency Medicine Journal : EMJ. 2011;28(7):594-8. doi:10.1136/emj.2009.085803.

Background: The recent popularity of domestic trampolines has seen a corresponding increase in injured children. Most injuries happen on the trampoline mat when there are multiple users present. This study sought to examine and simulate the forces and energy transferred to a child's limbs when trampolining with another person of greater mass.

Methods: The study used a computational biomechanical model.

Results: The simulation demonstrated that when two masses bounce out of phase on a trampoline, a transfer of kinetic energy from the larger mass to the smaller mass is likely to occur. It predicted that when an 80 kg adult is on a trampoline with a 25 kg child, the energy transfer is equivalent to the child falling 2.8 m onto a solid surface. Additionally, the rate of loading on the child's bones and ligaments is greater than that on the accompanying adult.

Conclusions: Current guidelines are clear that more than one user on a trampoline at a time is a risk factor for serious injury; however, the majority of injuries happen in this scenario. The model predicted that there are high energy transfers resulting in serious fracture and ligamentous injuries to children and that this could be equated to equivalent fall heights. This provides a clear take-home message, which can be conveyed to parents to reduce the incidence of trampoline-related injuries.

5.
Varus Shearing Force Is a Main Injury Mechanism of Pediatric Trampoline-Related Injury in Addition to Compressive Axial Loading.

Kim KH, Kim HS, Kang MS, Park SS.

PloS One. 2019;14(6):e0217863. doi:10.1371/journal.pone.0217863.

Background: Many case studies have been published about trampoline-related injury (TRI); however, a comparative study could allow a more specific analysis of the characteristics of TRI, and enable more differentiated approaches to prevent such injuries. We investigated the injury mechanism of TRI in children compared with other pediatric trauma.

Methods: Of 35,653 children (age 0-18 years) who visited the pediatric emergency department after traumatic injuries from January 2011 to June 2017, 372 patients with TRI (TRI group) were retrospectively identified. Among the remaining 35,281 patients with other trauma (non-TRI group), 372 were 1:1 matched to the TRI group according to sex, age, injured body part, and body weight (matched-control group). The patients' data, injured site, and injury patterns were compared between the groups.

Results: The most frequently injured body part was the knee/lower leg in the TRI group and the head in the non-TRI group. The most frequent injury types were fractures in the TRI group and open wounds in the non-TRI group. In the comparison between the TRI and matched-control groups, the most common lower-extremity fractures were proximal tibial fractures with varus angulation in the TRI group and tibial shaft spiral fractures in the matched-control group. For the upper extremities, the risk of lateral condylar humeral fracture was higher in the TRI group. The TRI group presented more physeal involvements.

Conclusions: The risks of varus stress injury (proximal tibial fracture with varus angulation in lower extremity and lateral condylar humeral fracture in upper extremity) were higher in the TRI group than in matched-control group. Thus, varus shearing force seems to be an important injury mechanism in TRI in addition to compressive force. This varus force may increase the risk of physeal injury by generating additional shear force on the physis.