Documentation:FIB book/Wrist Injuries and Injury Prevention Methods in Snowboarding Falls

Overview

Introduction

Snowboarding poses a high risk of wrist trauma, most commonly distal radius fractures, due to the instinctive use of outstretched hands to break both forward and backward falls. Wrist injuries mostly occur in beginner to intermediate level snowboarders from simple falls as seen in a study in Japan and account for roughly 20% of all snowboarding-related accidents. Wrist guards reduce the risk of fractures by up to 50% using splints and padding to lower the transmitted load to the wrist, but are only worn by about 16% snowboarders according to Thoraval et al. (2013).

We will be discussing common wrist injuries and the effectiveness of wrist guards by conducting a literature review on lab and real world tests to determine their damping and bending performance. We will specifically use bench standard tests, rig impacts, and on-slope field data to link laboratory metrics to real falls. Since there are no standards for snowboarding wrist guards at the moment, we will be also comparing inline skating wrist guard standards (EN 14120) to determine whether they perform sufficiently for snowboarding purposes.

EN 14120

The EN 14120 standard enforces sufficient protection of inline skating protectors for falls on flat terrain. This standard specifies that wrist guards comply with the standard if peak forces measured in impact tests with 3-7 J of energy are under 3000 Ns with maximum transmitted forces of 1025 N . This standard may not be deemed fit for snowboarding due to limitations in its testing methods since other studies have shown that the energy transmitted through the wrist during a snowboarding fall is about 13.5-22.5 J. One study shows that the test setup indicated in the standard only transmits a peak load of 1035 N while their new test transmits a load of 2643 N after adjustments to the energy applied and impact geometry.

A circular striking face of at least 40mm x 40mm is expected to be dropped onto the test specimen but the curvature of this surface is not provided. This may be an area that requires improvement to mimic falling conditions in snow. To mimic the wrist and palm, an anvil with a curvature of 100mm is connected to the protector.

Stiffness is measured through a test that applies a moment between 2-3 Nm to a wrist mockup. The wrist guard falls within the standard if the wrist moves between 40 and 55 degrees.

Wrist Fracture Types and Causes

Wrist injuries are the most common type of snowboarding injuries which account for contusions, sprains, distal radius/ulna fracture, carpal fracture, scaphoid fractures, and forearm fractures. These injuries occur due to forward and backward falls on a snowboard, with the latter attributing to twice as many fractures as the former.

The anatomy of the wrist is made up of two forearm bones, radius and ulna, connected to two rows of carpal bones (See Figure 1). Distal radius fracture, the most common wrist injury, occurs due to an attempt to break a fall with outstretched arms, which result in a radius forearm bone fracture. The term “distal” refers to the end of the radius closest to the wrist. Specifically, the injury occurs due to a compressive load applied to a hyperextended wrist. Hyperextension occurs when wrist extension exceeds the normal range of motion, which is 60°- 75° for extension and 60°- 82° for flexion.

Figure 1 - Anatomy of the Hand and Wrist

The second most common wrist injury is a scaphoid fracture, also commonly caused by falls with outstretched arms. The scaphoid is one of the eight small bones, the carpal bones, in the wrist joint (See Figure 2). Specifically, the scaphoid is attached to the radius at the wrist.

Figure 2 - Carpal Bones Anatomy

Recent on-slope measurements provide direct biomechanics evidence of how these wrist injuries occur during snowboarding falls. The study used instrumented gloves equipped with force and angle sensors to record data from 128 fall events among riders of varying experience levels. The results showed that snowboarders often experience wrist extension angles approaching terminal values of 80-90°, which coincide with the range associated with distal radius fractures. The mean peak impact force was 266 ± 232 N, with a corresponding wrist moment of 13.5 ± 16.6 Nm. Although these loads are below the 2 - 2.5 kN fracture threshold observed in cadaver testing, they represent frequent exposure to sub-injury forces capable of causing sprains and carpal fractures.

Much of the large ± 232 N variability comes from differences in fall direction: backward falls were found to generate significantly higher forces than forward falls, and beginners sustained greater loads than advanced riders, which means that skill level and fall direction are critical factors that influence injury risk. Although backward falls produce higher loads, laboratory standards generally do not differentiate fall direction; instead, they aim to capture the overall loading range seen across both forward and backward falls. These findings highlight that even moderate impacts can subject the wrist to near-injury loading, suggesting that properly designed wrist protectors could substantially reduce the likelihood or severity of these injuries.

Methods

Wrist protectors function by absorbing impact energy through soft materials like foam or by limiting wrist extension to keep it within a safer range. To further understand and evaluate the effectiveness of snowboard wrist protectors, many studies have developed a variety of different mechanical testing methods. Some have been designed to meet standardized safety requirements, such as the EN 14120, while others have been developed to simulate realistic fall dynamics and impact loads.

Schmitt et al. (2011) applied the EN14120 roller-sports safety standard to evaluate the damping and stiffness of fifteen different wrist protectors, which included eight snowboarding gloves with integrated protectors, seven standalone wrist guards, and three inline-skating guards. The biomechanical importance of this work demonstrates how these devices reduce the loads transmitted to the wrist during a fall through two standardized tests. The first is an impactor drop test using a 2.5 kg mass to deliver 5 J of energy to the palm, and the second is a bending test that applies a constant torque of 3 Nm to the wrist. Their impact test quantifies how effectively the protector lowers the peak force during a palm strike, while their bending test evaluates wrist extension stiffness, which directly relates to preventing hyperextension injuries. The standard defines acceptable impact absorption abilities if the peak load remains below 3 kN and allowable stiffness as 35-55° of extension at the specified torque. However, EN14120 uses impact energies far below those documented in real snowboard falls, which often exceeds the 30 J used, suggesting that the standard doesn’t fully capture the dynamic, high loading rate of real falls.

Because of this limitation, other research such as the study done by Adams et al. (2021) and Greenwald et al. (1998) focused on employing more realistic impact simulations to simulate snowboarding fall conditions. In the study done by Adams et al. (2021), they developed a 1.5 m pendulum arm with an effective mass of 10 kg to simulate the impact velocity of 3-5 m/s and 40 J of energy onto a surrogate wrist, which more closely matched the expected energy levels of real falls. The surrogate wrist is made up of an aluminum hand, a steel forearm core that represents the bones, and a hinged wrist joint to allow for extension. The pendulum also has the added feature of using a 100 mm thick polychloroprene layer on the arm impact point to represent the soft tissue of the hand. A three-axis dynamometer located at the base of the surrogate wrist measured impact forces, while potentiometers recorded wrist and pendulum angles, and a high speed camera was used to verify contact and record rebound of the pendulum arm. Impact tests were then repeated on twelve different commercial wrist protectors which included stand alone and integrated glove designs, with unprotected wrist surrogate tests conducted for comparison. Through these tests, the study was able to gather data on peak vertical force (kN), time to peak vertical force (ms), and percentage of the energy absorbed by the wrist protector based on the reboarding angle of the pendulum arm.

Taken together, both studies provide valuable insight into the methods currently used to evaluate wrist protection. The standardized experiments performed by Schmitt et al. (2012) allow us to look at direct comparisons with regulatory limits, while the pendulum impact test represents higher energy impacts more realistic snowboarding fall conditions and thus offers greater biomechanical relevance.

Results

The following results compare the mechanical response of the wrist under protected and unprotected conditions. Key parameters such as peak impact force, moment, and wrist extension angle were used to evaluate the effectiveness of wrist guards in reducing load and limiting hyperextension during snowboarding falls. Quantitative findings are presented in Table 1 and Table 2.

Table 1. Protected Quantitative Comparison

Protected Condition	Bending	Drop
Peak Impact Force (N)	N/A	Reduced by ≥ 1.5 kN (approx. 4,700 N)
Wrist Extension (°)	35–55° at 3 Nm, > 55° at 16 Nm	N/A

Table 2. Unprotected Quantitative Comparison

Unprotected Condition	Pendulum	On-slope grove
Peak Impact Force (N)	6200 N	266 ± 232 N
Wrist Extension (°)	N/A	80 ± 15°

Tests with Protection

1. Impact Damping: Only 2 of 8 snowboarding gloves met the 3 kN requirement at 5 J. 3 of 7 snowboarding wrist guards passed, compared with all inline-skating wrist guards. Failures typically occurred at 1 - 2 J, showing insufficient damping capacity for realistic snowboarding falls.
2. Bending Stiffness: Most protectors limited wrist extension to 35 - 55° at 3 Nm, meeting EN 14120. However, none maintained this limit at 16 Nm, and all exceeded 55°, demonstrating inadequate stiffness at real-world torque.

The peak vertical force was reduced by at least 1.5kN across all the different protectors, and they were able to increase the time to peak force by roughly 20ms or more, which shows that the protectors have better energy dissipation functions. Furthermore, it was found that the protectors were able to increase energy absorption of the impact by 17-37% compared to the unprotected surrogate.

Tests without Protection

1. The impacts recorded on the unprotected surrogate produced an average peak vertical force of 6.2kN.
2. Without protection, the maximum moment was 13.5 ± 16.6 Nm with a mean wrist extension angle of 80 ± 15°. Beginners experienced higher force than advanced riders, while adults generate greater loads and moments than younger riders. Although no injuries occurred, many falls resulted in wrist angles near terminal extension (80-90°), approaching the range associated with distal radius fractures. The observed loading conditions correspond to impact energy around 13-22 J, which is far exceeding the 3-7J threshold used in EN 14120, which means the real snowboarding falls without protection expose the wrist to substantially higher loads than current test standards.

Overall, the results show a clear pattern. Wrist protectors do lower impact forces and limit how far the wrist bends back, but their effectiveness depends on how hard the fall is. They perform well in lower-energy lab tests, but they don’t always hold up during the higher-energy impacts that happen in real snowboarding. When we look at all the studies together, they show that wrist protection helps, but current designs and standards may not fully match what actually happens during real falls.

Discussion

Protected vs. Unprotected Impact Conditions

Comparing protected and unprotected conditions reveals that wrist guards reduce loading but remain limited under realistic snowboarding impact. Laboratory tests showed reduction of about 1.5 kN in peak force. Field data without protection recorded average impact forces of 266 N and wrist angles near 80-90°, approaching the range for distal radius fracture. These results indicate that wrist guards can lower acute forces and restrict wrist motion, but they may fail under higher torques. Overall both datasets suggest protection helps reduce injury severity but also show the need for standards tailored to snowboarding loads and motions.

Together, these findings show that protectors help, but the gap between lab impacts and real falls is large enough that test results alone cannot fully predict injury risk.

Limits of Current Standards

Across studies, bench setups under-estimate real fall energies, rig and field work show higher forces/angles and epidemiology identifies beginners as highest risk. Together, this supports snowboarding-specific standards and behavioral prevention, such as teaching riders to avoid stiff-armed bracing and instead roll onto the forearms or torso to reduce wrist loading. These converging lines of evidence explain why inline-skate thresholds fail on snow.

The 5 J impact energy prescribed by EN 14120 is unrealistically low compared to the 13-22 J measured in snowboarding falls. While the current 3 kN pass threshold is appropriate for preventing distal radius fractures, testing should include higher impact energies to ensure maximal protection under realistic conditions. Similarly, the bending range of 35-55° appears too conservative, as actual snowboarding falls can involve wrist angles near 80° without immediate injury.

This means bending tests may underestimate the wrist’s actual range during a fall and overestimate how well a device performs.

Design Trade-Offs and Controversies

The study also emphasized comfort and wearability as important for compliance: overly stiff guards reduce range of motion and may discourage consistent use. A key design trade-off is whether increasing wrist-guard stiffness improves protection or simply shifts injury risk elsewhere. While stiffer guards limit wrist extension, they can also redirect impact forces up the arm and increase elbow or shoulder loading. Conversely, more flexible guards reduce proximal load transfer but may not adequately protect the distal radius during higher-energy falls. Future standards should define a stiffness range that prevents wrist fractures without elevating proximal joint moments.

We acknowledge that the papers discussed differ in their test geometries, loading conditions, and impact force levels, which complicates direct comparison across studies. We believe that developing snowboarding-specific testing standards would improve accuracy of evaluating wrist-guard performance under realistic fall conditions. By refining both geometry and loading parameters, future test protocols could better assess the effectiveness of wrist guards protection, ultimately producing designs that prevent fractures without sacrificing comfort or mobility. A snowboarding-specific performance standard should therefore use ≥15-20 J impact, snow-like compliant anvils, and an expanded allowable extension range that reflects real fall biomechanics.

Conclusion

Wrist protectors help reduce the risk of fractures by lowering the load transmitted to the wrist during a fall. A deeper understanding of these injury mechanisms can help snowboarders not only choose effective protective gear but also learn how to fall in ways that minimize stress on the wrist. Beginner and intermediate level snowboarders would benefit from using them but should still exercise caution when snowboarding since the load from the wrist may be transferred into the shoulders and elbows.

In general, wrist protectors reduce the likelihood of wrist fractures to a certain degree but do not prevent them. Current testing standards such as EN 14120, originally designed for inline skating, do not accurately reflect snowboarding falls, which involve higher impact energies (13-22 J) and larger wrist extension angles (up to 80-90°). To improve safety, a snowboarding-specific performance standard should be developed that accounts for realistic energy levels, fall directions, and snow-surface conditions. Looking ahead, future research should focus on:

1. Developing a snowboarding-specific test protocol with ≥15 J impact energy and snow-compliant anvils such as the setup suggested in the study by Thoraval et. al., 2013.
2. Defining an optimal stiffness range that prevents fractures without transferring load to proximal joints.
3. Evaluating cold-temperature performance of materials used in wrist guards.

By combining improved testing standards, biomechanical insight, and rider education, snowboarding wrist protection can evolve from trial-and-error equipment design into a data-driven safety system that effectively reduces injury risk without compromising performance or mobility.