Blow the whistle: a cross-sectional video-analysis study examining bodychecking, suspected injuries and penalisation of illegal contacts in youth ringette

Abstract

Objectives

To evaluate physical contact (PC), head contact (HC) and suspected injury incidence rates (IR) in youth ringette players across different age groups and levels of play, using video analysis.

Methods

This is a cross-sectional video-analysis study of competitive youth ringette games (regular season, provincial and national tournaments) filmed during the 2021–22 season in a major Canadian city. Participants included under 16 years of age (U16; ages 14–15 years) and under 19 years of age (U19; ages 16–18 years) ringette players competing at the A and AA levels (top two most elite levels). A total of 35 games were analysed representing 3256 team-minutes.

Primary outcomes included the IRs of bodychecking (illegal trunk PC) and HCs (direct—HC₁; indirect—HC₂). Secondary outcomes included suspected injury and concussion rates and the proportion of illegal contacts (bodychecks and HC₁s) penalised.

Results

The bodychecking IR was 17.34/100 team-minutes (95% CI 14.80 to 20.33) and HC IR was 19.09/100 team-minutes (95% CI 16.74 to 21.78). Few bodychecks (29%) and HC₁s (7%) were penalised. There were no differences in bodychecking or HC rates between age groups or level of play. Higher bodychecking IRs were found in provincial games compared with regular season. The most common mechanism for suspected non-concussion injuries was bodychecking. Suspected concussions most often resulted from HC₂s (primarily following bodychecking).

Conclusion

High rates of bodychecking and HCs were found across all ages and levels of play, despite rules prohibiting these actions in ringette. Injury prevention efforts should target reducing bodychecking and HC behaviours to improve player safety.

WHAT IS ALREADY KNOWN ON THIS TOPIC.

WHAT THIS STUDY ADDS

• This study shows evidence that bodychecking and HCs occur frequently in youth ringette, at different age groups and levels of play, with low rates of penalisation of these illegal actions.

HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY

• This study highlights a critical gap in rule enforcement in youth ringette and may inform the development of ringette-specific injury prevention strategies targeting rules prohibiting illegal contact to reduce injury risk in female youth ringette players.

Introduction

Ringette is a common ice sport played in many countries (Canada, USA, Finland, Sweden, Slovakia and the Czech Republic) by primarily females.1,3 There are many similarities and differences to ice hockey, with one key difference being the use of a straight stick and a rubber ring instead of a bladed stick and a puck.^{2 4} There are also many rule differences, including that players must pass the ring over each blue line, only three players from each team are allowed inside the free play line (small red line on top of the circles in the offensive/defensive zones) and the use of a 30-second team-possession shot clock.² Similar to female ice hockey, bodychecking (ie, excessive contact with another player²) is prohibited at all ages and levels of play.^{2 4 5} Despite being played by over 33 000 players in Canada annually⁶ (compared with 108 000 woman and girl ice hockey players annually⁷), very few studies have investigated ringette-specific injury epidemiology.

Two video-analysis studies examining in-game physical contact (PC) behaviours have been completed comparing ringette and female ice hockey at both the university and elite youth levels (under 16 years (U16)AA for ringette, under 15 years (U15)AA for female ice hockey; ‘AA’ referring to the highest level of competitive play).^{8 9} In both studies, it was found that ringette had significantly higher rates of bodychecking (university=98% higher rates, youth=160% higher rates), head contacts (HC; university=68% higher rates, youth=89% higher rates) and suspected injuries including concussions (threefold higher rates at both university and youth) compared with female ice hockey.^{8 9} These few studies have shown the need for further investigation into the burden of injury in ringette at different age groups and levels of play. Importantly, these studies were designed as sport-to-sport comparisons and therefore do not describe how contact behaviours vary within ringette itself across age groups, levels of play or game types.

Video analysis provides a practical method for examining contact behaviours and suspected injury mechanisms in fast-paced ice sports, particularly when medical confirmation is not feasible. For the present study, video analysis was used because no concurrent injury surveillance data were available for the games analysed. Although video-only approaches cannot confirm diagnosis such as concussion, they have been validated in women’s and youth team sports and offer valuable insight into patterns of PC.

The purpose of this study was to use video analysis to compare PC, HC and suspected concussion and non-concussion injury incidence rates (IR) between the age groups, U16 (ages 14–15 years) and under 19 years (U19; ages 16–18 years), considering two top levels of ringette (A, AA) and different game types (regular season, provincial tournament and national tournament). Based on previous video-analysis research, we hypothesised that PC, HC and suspected injury rates would be high across all groups, with higher rates expected in older age groups, higher competitive levels and tournament games. This study is the first to examine contact behaviours exclusively within ringette across multiple ages and levels of play.

Methods

Design and participants

This was a cross-sectional video-analysis study. Participants included ringette players playing in the U16 and U19 age groups at the A or AA level in a single major Canadian city. Video footage was of games filmed during the 2021–2022 regular season, provincial and national level (AA only) tournaments. All video data were anonymous, so individual player consent was not required. This study was a subcohort of a larger pan-Canadian prospective cohort study.¹⁰

Video footage collection

Video footage was collected by research assistants trained on the filming equipment and proper filming technique at various ice arenas, with the camera located in one of two locations. The first and most ideal location was at the highest location near centre ice (90% of recordings). If this location was not available (eg, thick netting, no or low stands), then the camera was positioned at one of the corners at ice level (10% of recordings). In addition to the previous two video-analysis studies in ringette and female ice hockey, video analysis has been widely used as a valid method for understanding injury mechanisms in multiple sports.11,19

Sample size and game selection

Based on previous video analysis in university ringette players, there were an estimated 10.49 direct HCs (HC₁) per 100 team-minutes. Since HC₁s were found to account for about 3% of the total number of PCs, HC₁ rates were used to calculate sample size to obtain a more conservative sample size. Assuming similar rates of HC₁s at the U19 age group, AA level or tournament session and to detect a clinically relevant difference as small as 30% at the U16 age group, A level or regular season session, a total of 2830 team-game minutes were required (two-sided α=0.05, 1-β=0.80). This translates to 1415 team-game minutes required per category (age group, division or session type) or 16 games per category (one game is approximately 80–92 team-minutes). An additional four games at both the U16AA and U19AA level were analysed from the National Championships for additional comparison (National Championships only occur at the AA level). All possible regular season and tournament games were filmed. Each game that was filmed was assigned a game number by one of the research team members. In the case where an excess of games was filmed for a category, random selection of games was completed using a random number generator matched to the game number. All round robin games in the tournaments were filmed for teams who were part of the SHRed study, and semi-finals and finals were filmed if the teams continued to those stages of the tournament. All games were matched on game type (ie, the same number of round robin, semi-final and final games were used at each age and level of play). A breakdown of games analysed per category is shown in table 1. Only three games from the U19A regular season were analysed as only three games were able to be filmed during the season.

Table 1. Overall games analysed by each age group (under 16 years (U16); under 19 years (U19)), level of play (A and AA) and session type (regular season, provincials and nationals).

Age group	Division	Session type		Nationals
		Regular season	Provincials
U16	A	4	4	N/A
	AA	4	4	4
U19	A	3	4	N/A
	AA	4	4	4

National games only occur at the AA level.

Outcome measures

Dartfish V.10.0 video-analysis software²⁰ was used to analyse gameplay frame-by-frame to examine player behaviours with a ringette-specific custom-made tagging panel. These methods were adapted from previously validated video analysis in male youth ice hockey (eg, terminology updated to reflect ringette-specific elements such as ‘ring carrier’ instead of ‘puck carrier’) and previously used in both university and youth-level ringette and female ice hockey.^{8 9 21} Raters for the study included a gold standard rater with extensive experience in analysing team ice sports and two trained raters with a background (eg, player and/or coach) in ringette. Inter-rater reliability was completed between each rater and the gold standard rater until an average of 90% or greater was reached on various PC metrics (minimum >70% reliability in each category). Intrarater reliability was also completed 1 month after initial inter-rater reliability to ensure 90% agreement was still being met with their own original coding.

Validated PC metrics included trunk contacts classified by severity into five levels (table 2).^{8 9 21} Levels 1–3 were classified as lower-intensity body contact and levels 4–5 were classified as higher-intensity bodychecking. Other contacts included those made with the limbs or stick (eg, pushing, hitting, holding, cross-checking). Each PC was tagged with the contact zone on the ice (figure 1), directionality of the player giving the contact (offensive or defensive), intention of the contact (deliberate—player purposely skated/moved their body towards the opponent or non-deliberate—accidental contact), impact the contact had on the play (operational—impacted the play, non-operational—no impact on the play), if the contact was on or by the ring carrier and if a penalty was assessed by the referee (and penalty type). Penalty type was determined using the Ringette Canada 2019–2022 Official Rulebook, which showed the referee signals for penalty type and was matched to the signals made by the referees in the video footage.⁴ HCs that occurred as part of a PC were classified as either direct contact by opposing players (HC₁) or indirect contact to the head after a collision via the boards, glass or ice surface (HC₂). Suspected injuries were assessed based on criteria adapted from previous video analysis from professional soccer, where at least one of the criteria needed to be met.¹¹ Criteria included: the referee stopped play for the injury, the player remained on the ice for longer than 15 s after contact and the player appeared to be in pain or required medical attention. Suspected concussions were assessed using 17 previously used video signs of concussion from professional sport based on expert consensus (eg, lying motionless, dazed, slow to get up, clutching at head).¹² Suspected injuries, including concussion, were assessed individually by each of the three raters and were included in the analysis if at least two of the raters agreed that the criteria were met. These methods for determining suspected injuries and concussions have also been validated in a non-professional setting in women’s rugby and used by coders with no clinical background.¹⁶

Table 2. Trunk and other physical contact definitions based on Malenfant et al^{8 9 21}.

	Definition
Trunk physical contact (PC)
Level 1	Very light contact between two stationary players
Level 2	Light contact between two players moving in the same relative direction
Level 3	Moderate contact between two players moving in the same relative direction
Level 4	Heavy contact, with one player forcefully exerting one’s body into the opposing player, usually moving in the opposite direction. Minimum requirement of a bodycheck
Level 5	Excessive, deliberate contact from one player with the intention beyond impeding the progress of the opponent, moving in the opposite direction
Other physical contact (PC)
Limb	Contact using one or both upper or lower extremities, such as pushing, punching, holding or kicking
Stick	Contact to the body using the stick, such as slashing or hooking

Unshaded region (levels 1–3) represents body contact trunk physical contacts; shaded region represents bodychecking trunk physical contacts.

Figure 1. Zones of the ringette arena adapted from Malenfant et al.^{8 9 21} The free play line is the thin line located above the circles in the offensive/defensive zones and is the location that only three players from each team are allowed to enter (excluding the goalie).².

Data analysis

Data were analysed using Stata V.17.1 statistical software.²² Multivariable (age and level of play) Poisson regression analyses adjusted for filming location and clustered by team-game and offset by game length (minutes) were used to report IRs expressed as the number of contacts per 100 team-minutes and IR ratios (IRR) to compare PC, HC and suspected injury and concussion rates between age groups, level of play and game type in ringette. IRs, IRRs and frequencies were used to describe PC mechanisms and characteristics. The proportion of bodychecks and HC₁s penalised was also reported.

Guidelines

We used the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline to draft this manuscript and the STROBE reporting checklist when editing, included in online supplemental file.²³

Results

There were 10 025 PCs (including 5278 trunk PCs) recorded in the 1628 minutes (3256 team-minutes) analysed. These PCs had a high percentage of deliberate contacts (95%), done on or by the puck carrier (90%), initiated by the defensive player (88%) and were operational to the play (96%). The most common location for total trunk contacts, bodychecks and HCs was in open ice (zone 3; trunk contacts=52%, bodychecks=53%, HC=46%) followed by in front of the net (zone 5; trunk contacts=17%, bodychecks=19%, HC=19%).

The IR of total bodychecking was 17.34/100 team-minutes (95% CI 14.80 to 20.33). A total of 29% of bodychecks was penalised (penalty type assessed: 65% body contact, 10% boarding, 6% major body contact or boarding, 7% hooking, 5% interference and tripping and 1% cross checking and unsportsmanlike). The IR of total HC was 19.09/100 team-minutes (95% CI 16.74 to 21.78) with a HC₁ rate of 13.72/100 team-minutes (95% CI 11.89 to 15.83) and a HC₂ rate of 5.37/100 team-minutes (95% CI 4.52 to 6.39). Only 7% of HC₁s were penalised, with no major penalties being assessed (penalty type assessed: 66% body contact, 15% high sticking, 7% interference, 4% hooking, slashing and tripping).

The video-identified suspected injury IR was 1.53/100 team-minutes (95% CI 1.13 to 2.09), which included suspected concussion (IR=0.74/100 team-minutes; 95% CI 0.48 to 1.13) and non-concussion injuries (IR=0.80/100 team-minutes; 95% CI 0.50 to 1.27). Overall, 92% of the suspected injuries were a result of deliberate contact, with 70% of suspected concussions and 67% of suspected non-concussion injuries involving bodychecking. Suspected concussions resulted from HC₁s 37.5% of the time (78% following bodychecking) and HC₂s the remaining 62.5% (73% following bodychecking) of the time.

The following sections present comparisons between age groups, levels of play and game types. These results should be interpreted with caution, as several CIs were wide and the study may have been underpowered to detect smaller differences between groups.

Differences between age groups

When looking by age group (U19 relative to U16) and adjusting for level of play and filming location, there were no significant differences in bodychecking (IRR=0.96; 95% CI 0.71 to 1.30), total HC (IRR=0.88; 95% CI 0.68 to 1.13), HC₁ (IRR=0.90; 95% CI 0.68 to 1.18), or HC₂ (IRR=0.83; 95% CI 0.60 to 1.16) IRs (figure 2). Further analysis comparing age group within the levels of play (U19AA relative to U16AA; U19A relative to U16A) also revealed no significant differences for total PCs, bodychecking, total HCs, HC₁s, HC₂s or suspected injuries. However, the U19AA group had lower rates in all categories compared with U16AA (online supplemental table S1).

Figure 2. Comparison of incidence rates (IRs) for bodychecking (level 4–5 intensity), total head contacts (HCs), direct HC (HC₁) and indirect HC (HC₂) between ringette players under 16 years (U16; ages 14–15 years) and under 19 years (U19; ages 16–18 years) adjusted for level of play and filming location. IR ratios (IRR) and 95% CIs were reported and adjusted for cluster by team-game and offset by game length (min).

Differences between level of play

When looking by level of play (AA relative to A) and adjusting for age group and filming location, there were no significant differences in bodychecking (IRR=1.32; 95% CI 0.97 to 1.79), total HC (IRR=0.96; 95% CI 0.74 to 1.23), HC₁ (IRR=1.07; 95% CI 0.81 to 1.40) or HC₂ (IRR=0.73; 95% CI 0.52 to 1.01) IRs (figure 3). Further analysis comparing level of play within the age groups (U16AA relative to U16A; U19AA relative to U16AA) found no differences for total PCs, bodychecking, total HCs, HC₁s, HC₂s or suspected injury IRs (online supplemental table S2).

Figure 3. Comparison of incidence rates (IR) for bodychecking (level 4–5 intensity), total head contacts (HCs), direct HC (HC₁) and indirect HC (HC₂) between the two top levels of ringette players (A and AA) adjusted for age group and filming location. IR ratios (IRR) and 95% CIs were reported and adjusted for cluster by team-game and offset by game length (min).

Differences between game type

When looking by game type and adjusting for age group, level of play and filming location, relative to regular season games, a 59% higher rate of bodychecking was found in provincials (figure 4). No other differences were found between game types for bodychecking, total HC, HC₁ or HC₂ IRs.

Figure 4. Comparison of incidence rates (IR) for bodychecking (level 4–5 intensity), total head contacts (HCs), direct HC (HC₁) and indirect HC (HC₂) between three different game types (regular season, provincials and nationals) adjusted for age group, level of play and filming location. IR ratios (IRR) and 95% CIs were reported and adjusted for cluster by team-game and offset by game length (min). *Statistically significant, 95% CI does not include 1.

Discussion

Previous video-analysis studies comparing ringette and female ice hockey at the university and elite youth level (U16AA for ringette, U15AA for female ice hockey) showed higher rates of bodychecking, HC and suspected injuries in ringette, prompting the need for further analysis to examine different age groups and levels of play within ringette.^{8 9} This study compared PC, HC and suspected injury IRs between U16 and U19 and two levels of play (A and AA) in youth ringette. Because this was a cross-sectional descriptive video-analysis study, causal relationships cannot be inferred from these findings.

Bodychecking rates

The rate of bodychecking found in this study (IR=17.34/100 team-minutes; 95% CI 14.80 to 20.33) is similar to the rate of bodychecking found in ringette in two previous studies at the U16AA (IR_{RingetteYouth}=21.29/100 team-minutes, 95% CI 13.57 to 33.41) and university-level (IR_{RingetteUniversity}=15.01/100 team-minutes, 95% CI 10.45 to 21.56).^{8 9} These rates were significantly higher than female U15AA ice hockey (IR_HockeyYouth=8.09/100 team-minutes, 95% CI 6.31 to 10.36) and university-level (IR_{HockeyUniversity}=7.58/100 team-minutes, 95% CI 5.80 to 9.92).^{8 9} These findings show that high rates of bodychecking are being seen at multiple age groups and levels of play within ringette compared with female ice hockey, despite bodychecking being disallowed. This current study found that 95% of all contacts were deliberate, with only 29% of bodychecks being penalised. Given that 70% of suspected concussions and 67% of suspected non-concussion injuries involved bodychecking, this is a critical area to be targeted for future injury prevention research to help reduce the burden of injury in ringette. Bodychecking rates were significantly higher in provincial tournament play compared with regular season games, suggesting that games with higher importance may result in players changing their style of play, resulting in more bodychecks occurring in a game. This may also be a result of referee style changes in tournament games, allowing for more bodychecks to occur, changing the behaviours of the players. Since there were no differences in bodychecking IRs when comparing U16 and U19 age groups or A and AA levels, prevention strategies should target high bodychecking behaviours at all ages and levels of play.

These findings raise important questions as to why high rates of bodychecking and low rates of penalisation persist despite rules prohibiting such behaviours. Possible contributing factors may include sport culture, officiating variability and unclear or inconsistently enforced rules.²⁴ Future research should explore these contextual factors, including the experiences and perspectives of players, coaches, officials and governing bodies, to better understand the mechanisms driving illegal contact and gaps in enforcement. We did not collect information on referee training, certification level, experience or consistency across games, so we are unable to draw conclusions about officiating practices from these findings.

Head contact rates

This study found high rates of HCs (IR=19.09/100 team-minutes; 95% CI 16.74 to 21.78), despite rules banning HCs in ringette. Although there is no independent HC penalty in ringette like there is in ice hockey,²⁵ if a minor penalty has occurred and initial contact is made to the head, then a major penalty should be assessed.⁴ Therefore, there should be high rates of HC₁ being penalised as major penalties in ringette. However, only 7% of HC₁s were penalised, with no major penalties being assessed when a penalty was given. This shows an opportunity for an improvement of referee enforcement of penalties associated with HC₁s. However, for this to occur, the referees also need the support from everyone involved (ie, coaches, parents, players and administrations). The HC₁ rate in the study (IR=13.72/100 team-minutes; 95% CI 11.89 to 15.83) was similar to rates found in the previous video-analysis studies of U16AA (IR_{RingetteYouth}=18.74/100 team-minutes, 95% CI 13.07 to 26.89) and university ringette (IR_{RingetteUniversity}=10.49/100 team-minutes, 95% CI 9.14 to 12.04), which were both significantly higher than female U15AA ice hockey (IR_HockeyYouth=9.02/100 team-minutes, 95% CI 7.19 to 11.32) and University-level ice hockey (IR_{HockeyUniversity}=7.49/100 team-minutes, 95% CI 5.50 to 10.20).^{8 9} This highlights the higher rates of HC₁s found in ringette compared with female ice hockey are present at multiple age groups and levels of play. When comparing across age groups and level of play, there were no significant differences found for total HC, including both HC₁ and HC₂.

Limitations

This study was limited by a single, fixed camera angle, which may have resulted in an underestimation of PCs and HCs occurring outside the frame of the camera. However, these would not result in a difference in the comparison between age groups, levels or game type, as all would have these limitations. The suspected injury and concussion criteria for video analysis used were designed for professional sports where they have multiple different angles and high-quality cameras. For this study, only one camera angle was used, so it would be more difficult to identify suspected concussions and injuries using the same criteria. Additionally, many injuries and concussions do not result in any visible signs and therefore will not be able to be identified without having injury records associated with the video footage. However, previous studies in women’s rugby union have validated this methodology for use in non-professional settings and by those with no formal medical background.¹⁶ Future directions may consider video analysis including validation of suspected injuries using a valid injury surveillance system. Due to differences in game types between levels of play (Nationals only at the AA level), perfect comparisons across levels of play are not possible. However, due to the importance of the National Championships at the AA level, we thought it was important to include in the analysis to have a better understanding of the full season for AA players. Lastly, due to the extensive amount of time required for video analysis (6–10 hours of analysis/per 40 min of game time), this study may have been underpowered to make some comparisons.

Research/policy implications

This study highlights the high rates of illegal contacts with low penalisation in youth ringette, indicating a critical gap between rule enforcement and gameplay. These findings may inform future research examining officiating practices, as well as the development of rule clarifications or education-based interventions targeting referees, coaches and players. Policy changes aimed at stricter enforcement of illegal contact rules may help reduce these illegal contacts and suspected injury rates in female youth ringette. Future research should examine the broader system influencing illegal contacts, such as officiating practices, rule interpretation and player or coach expectations to better understand why prohibited behaviours persist. Studies assessing the impact of referee training programmes, rule clarification interventions and behaviour-focused education for coaches and players may help identify effective prevention strategies. Policy actions could include developing standardised enforcement guidelines to support safer play across age groups and competition levels. Finally, integrating video analysis with a validated injury surveillance system would allow confirmation of injury outcomes and provide stronger evidence on which types of contact behaviours are most likely to result in injury.

Conclusion

This study demonstrated high rates of bodychecking, HC and suspected injuries with no significant differences found between the U16 and U19 age groups or A and AA levels of play. These rates were comparable to previous studies in ringette at the University and U16AA level which were found to be significantly higher than female ice hockey. Despite bodychecking and HC₁s being prohibited in ringette, there was a very low proportion of both penalised. It was found that most suspected concussions resulted from HC₂s (usually following bodychecking), so future prevention strategies may need to target these areas. Additionally, higher rates of bodychecking were found in provincial tournament games compared with regular season, so this may be an additional target area as most suspected concussion and non-concussion injuries resulted from bodychecking.

Data availability statement

Data are available upon reasonable request.