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Original article

Reducing musculoskeletal injury and concussion
risk in schoolboy rugby players with a pre-activity
movement control exercise programme: a cluster
randomised controlled trial
Michael D Hislop,1 Keith A Stokes,1 Sean Williams,1 Carly D McKay,1 Mike E England,2Simon P T Kemp,2 Grant Trewartha1►► Additional material areavailable. To view these files
please visit the journal online(http://d​ x.​doi.o​ rg/​10.​1136/​
bjsports-​2016-​097434).
1

Department for Health,
University of Bath, Bath, UK
Rugby Football Union,
Twickenham, UK

2

Correspondence toKeith A Stokes, Department for
Health, University of Bath, BathBA2 7AY, UK; ​k.​stokes@​bath.​
ac.​ukAccepted 12 April 2017
Published Online First
17 May 2017

ABSTRACT
Background Injury risk in youth rugby has received
much attention, highlighting the importance of
establishing evidence-based injury reduction strategies.
Aim To determine the efficacy of a movement control
exercise programme in reducing injuries in youth rugby
players and to investigate the effect of programme doseon injury measures.
Methods In a cluster-randomised controlled trial,
40 independent schools (118 teams, 3188 players
aged 14–18 years) were allocated to receive either theintervention or a reference programme, both of whichwere to be delivered by school coaches. The intervention
comprised balance training, whole-body resistancetraining, plyometric training, and controlled rehearsal of
landing and cutting manoeuvres. Time-loss (>24 hours)
injuries arising from school rugby matches were recordedby coaches and medical staff.
Results 441 time-loss match injuries (intervention,
233; control, 208) were reported across 15 938
match exposure-hours (intervention, 9083; control,
6855). Intention-to-treat results indicated unclear
effects of trial arm on overall match injury incidence(rate ratio (RR)=0.85, 90% confidence limits 0.61 to1.17), although clear reductions were evident in theintervention arm for concussion incidence (RR=0.71,
0.48 to 1.05). When trial arm comparisons were limited
to teams who had completed three or more weekly
programme sessions on average, clear reductions inoverall match injury incidence (RR=0.28, 0.14 to 0.51)
and concussion incidence (RR=0.41, 0.17 to 0.99) werenoted in the intervention group.
Conclusion A preventive movement control exercise
programme can reduce match injury outcomes, including
concussion, in schoolboy rugby players when comparedwith a standardised control exercise programme,
although to realise the greatest effects players should
complete the programme at least three times per week.

INTRODUCTION

To cite: Hislop MD,
Stokes KA, Williams S,
et al. Br J Sports Med
2017;51:1140–1146.
1 of 8   

The injury risk in youth rugby has received attention in the mainstream public and sports medicine
literature1 2 and has prioritised the formulation of
appropriate preventive measures.3 Musculoskeletal
injuries and concussion are prominent reasons fortime loss from sport for adolescent rugby players,45and significant youth sports injuries, in general,
have been implicated in long-term disability andcompromised quality of later life.6 7 Conditioning

the musculoskeletal system to tolerate external
forces, through enhancing strength and movement control, has been advocated as means of
reducing musculoskeletal injury risk, as indicatedby a growing evidence base that supports using
multifaceted preventive exercise programmes toreduce musculoskeletal injury risk across malesports such as basketball8 and soccer.9–11 Moreover,cross-sectional associations between neck strength
measures with concussion risk in young athletes
invite the possibility that interventions to enhanceneck strength may reduce concussion risk.12 The
injury patterns in rugby differ from other teamsports, owing to a greater frequency of concussion,
upper body and contact-related injuries,13 14 andso it is uncertain if introducing a targeted exercise
programme can reduce musculoskeletal injuries
and/or concussion in youth rugby players.
The efficacy of preventive exercise programmes
is dependent on several factors, of which thefrequency of programme use (ie, dose) may be one
such factor.15 Dose–response relationships havetypically been identified between programme use
and reductions in knee ligament injury incidence
in female sportspeople.16 17 Assessing the effects ofprogramme dose can be useful in reinforcing theoutcomes of intervention research and informing
subsequent implementation attempts.18
The aims of this study were to assess the efficacy of a pre-activity movement control exercise
intervention to reduce the incidence and burdenof rugby-related injuries in a schoolboy populationand to assess the influences of programme dose andcompliance on injury outcomes.

METHODS
Study design and recruitment

A cluster-randomised controlled trial was conductedacross independent school rugby teams over
one playing season (August to December 2015).
The study design was in accordance with the Consolidated Standards of Reporting Trials statement,19
and the trial was registered before recruitment (trial
registration number: ISRCTN13422001). Study
procedures were approved by the Research Ethics
Approval Committee for Health at the Universityof Bath.
Each school was treated as a cluster, within which
under-15 (U15), under-16 (U16) and under-18(U18) teams were allocated to the same trial arm.

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A priori sample size calculations were undertaken,20 incorporating injury data collected from a previous study on injuries inschoolboy rugby players.5 To discern a 30% reduction in matchinjury incidence at 80% statistical power, 13 schools per trial
arm were required. Seven additional schools were recruited ineach trial arm to account for attrition, yielding a target sample
of 40 schools. Schools deemed eligible to participate had on-site
access to physiotherapists or nurses who would treat all rugby-related injuries. Two hundred and twenty schools were identified
and sequentially contacted in randomised groups of 60 throughtrial invitation letters, emails and direct telephone calls to senior
members of the sport and rugby programmes until 40 schools
had provided written informed consent from a member of thesenior management team to participate in the trial. Schools
were randomly allocated to the intervention or control groups
on a 1:1 basis. The randomisation process for both recruitment
and allocation was completed independently of the researchteam. Schools were briefed that they would receive an exercise
programme to be delivered by the coaches to their U15, U16
and U18 teams, but were blinded to their trial arm allocation.
All U15, U16 or U18 players who participated in training or
match play at the school were eligible to participate in the trial.
Coach consent (in loco parentis), player assent and opportunity for parental opt-out (via school–parent mailing lists) weresought.
Coaches attended a pre-study workshop (typically 1 hour
duration) led by the research team at each school (June to July2015), at which they were introduced to either the intervention
or the control exercise programme and data collection materials,
in addition to being provided with a practical demonstration of
the programme. The practical demonstration of the programme
entailed coaches observing a research team member leading agroup of youth rugby players (U15, U16 or U18) through asession. Coaches across both trial arms received identicallyformatted data collection and programme materials (except forexercises). Programme materials included a filmed demonstration of the exercises (as a DVD), laminated cue cards (images
and key coaching cues for each exercise) and a booklet detailing
how to complete individual exercises. A further meeting was
arranged at all schools during pre-season for members of theresearch team to collect informed assent and baseline anthropometric information (standing height, seated height and bodymass) from all players involved in the trial.

The exercise programmes being trialled

The process of devising the intervention and control exercise
programmes have been reported elsewhere.21 Both programmes
comprised four phases, with progressions occurring via
increased difficulty and repetition volume of exercises. Phase 1
was devised for the pre-season period (typically 1–2 weeks’ duration). Both programmes progressed to phase 2 on the schoolterm commencing in September 2015, with two further planned
phase progressions occurring every 4 weeks until the end of thestudy in December. This timing enabled players to master the
exercises before being introduced to a more advanced phase.
Progression of the exercises was undertaken at the team level,with all players within the same age group teams completing thesame exercises at the same time. Phase difficulty was offset by
age group (ie, phase 3 of the U15 programme was similar indifficulty to phases 2 and 1 of the U16 and U18 programmes,
respectively) to maintain a sufficient stimulus for players at an
appropriate level. Both programmes were intended to take place
during the first 20 min of each pitch-based training session andmatch warm-up, and coaches in charge of each team acted asdelivery agents. Coaches were instructed to use the programmematerials, particularly the laminated cue cards during sessions, toassess movement execution in relation to the specified cues foreach exercise and to identify movements that could be improved.
The exercise programme allocated to teams in the intervention group integrated balance/perturbation training, resistancetraining, plyometric training and controlled rehearsal of sport-specific landing and cutting manoeuvres with verbal feedback andreinforcement of technique from the coach (see online supplementary material). The exercise programme allocated to thecontrol cohort was derived from currently regarded best practicewithin schoolboy rugby and featured a running-based warm-up,
dynamic stretching, controlled wrestling, mobility and speed/change of direction-related drills (without the specific feedback
instructions given in the intervention programme). The content
within both the intervention and control programmes were categorised into four separate parts (parts A, B, C and D) to aid thestructure of sessions and compliance reporting. A sample phasefrom the intervention exercise programme has been supplied forsupplementary reference.

Data collection

The definitions of a reportable injury (incurring a time loss ofmore than 24 hours), match exposure and training exposure(only pitch-based activities) were adapted from the consensus
statement for injury definitions and data collection proceduresin rugby union.22 Coaches recorded training exposure (lengthof each training session in minutes, number of players attending
training session), match exposure (match date, opponent name,list of players selected to play in each fixture) and programmecompliance at each session (completion of programme parts A,
B, C and D) on weekly paper-based or electronic report forms.
Programme compliance indicated the proportion of programmeparts that were completed at the team level across all exposures.
Coaches started the injury reports by logging the date that the
injury occurred, the injured player’s trial ID and playing position,and the event leading directly to the injury. School medical staff
recorded the injury location and a diagnosis when players visitedfor treatment. Logging the injury location and diagnosis alignedwith the first two levels of the Orchard Sports Injury Classification System (V.10).23 Coaches recorded the return-to-play date
(date of full participation in training or match play). A memberof the research team visited schools periodically (2–3 weeks’interval) during the study period to retrieve completed reportforms and to discuss study progress, but not to promote compliance or fidelity with using the programmes.

Statistical analyses

Statistical analyses were undertaken with IBM SPSS Statistics(V.22.0 for Windows). Trial arm comparisons across baseline
player characteristics (age, anthropometric characteristics andmaturity timing) were assessed using linear and logistic regression. The odds ratio (OR) generated from the logistic regression
was converted to a proportion ratio to permit analysis via magnitude-based inference.24
Intention-to-treat analyses compared injury measures between
the trial arms for all teams that provided injury and exposure
data, regardless of returning complete programme complianceor dose data. Trial arm comparisons were also undertaken on a
per-protocol basis with teams that maintained a mean programmecompletion rate of three or more weekly sessions, which represented a threshold for optimal compliance based on previous

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findings.25 The effects of intervention-only programme doseon injury were assessed by comparing injury measures between
teams that maintained an average of three or more sessions per
week with those who averaged completing the programmesless than three sessions per week. Overall match injury incidence (injuries/1000 player-hours) and burden (days lost/1000
player-hours) rates acted as dependent variables, with further
stratification by injury location and event. All estimations weremade using generalised linear modelling with a Poisson distribution, a log-linear link function and offset for hours of exposure
to generate rate ratios (RR) and 90% confidence limits (90% CL)
for injury incidence and burden values. RR and 90% CL wereassessed against predetermined smallest worthwhile effects ininjury outcome.26 The smallest worthwhile effects favouring
the intervention and favouring the control were given as
RR=0.90 and RR=1.11, respectively.27 Effects were deemed
clear if the per cent likelihood that the true effect favoured theintervention (RR below 0.90) was greater than 25%, and the OR
between favouring the intervention and favouring the control
was greater than 66 (ie, if the likelihood of effect favouring theintervention was 25% and the likelihood of effect favouring thecontrol was less than 0.5%); otherwise, effects were deemed
unclear. Effects were qualified against probabilistic terms fromthe following scale: <0.5%, most unlikely; 0.5%–5%, very
unlikely; 5%–25%, unlikely; 25%–75%, possibly; 75%–95%,
likely; 95%–99.5%, very likely; >99.5%, most likely.28

RESULTS

From a target population of 220 potentially eligible schools thatwere contacted for recruitment, 40 schools (118 teams, 3188
players aged 14–18 years) consented to participate in the trial
and were randomly allocated to the intervention or control
group (figure 1). Nine schools and 35 teams dropped out of the

Figure 1 Flow diagram presenting the recruitment and retention of participants through the study.
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Table 1

Summary and comparisons of player characteristics between the intervention (n=1325 players) and control (n=1127 players) groups

Trial arm

Intervention

Control

Effect size*(90% CL)(% higher | trivial | lower)† Inference

p ValueAge (years)

16.0±1.2

15.9±1.1

0.06 (0.00 to 0.14)(0 | 100 | 0%) Most likely trivial

0.19

Stature (cm)177.4±7.3

176.6±7.5

0.11 (0.03 to 0.19)(4 | 96 | 0%) Very likely trivial

0.03

Body mass (kg)74.7±12.972.5±13.1

0.17 (0.09 to 0.25)(27 | 73 | 0%) Possibly trivial<0.01>1 year post-PHV

642 (71%)586 (70%)

1.03 (0.91 to 1.16)(4 | 95 | 1%) Very likely trivial

0.68<1 year post-PHV

261 (29%)251 (30%)

Maturity offset (%)

Data presented as mean ± SD or as raw frequency (%) where specified.
*Effect sizes for age, stature and body mass expressed as Cohen’s d; effect size for maturity offset expressed as a proportion ratio.24†Percentage likelihood of effect being higher or lower is analogous to effect favouring intervention or control, respectively.
CL, confidence limits; PHV, peak height velocity.

trial, with data collected from 31 schools, 83 teams and 2452
players used for analysis (intervention, 17 schools, 44 teams,
1325 players; control, 14 schools, 39 teams, 1127 players).
Comparisons of baseline player anthropometric characteristics
between the trial arms are outlined in table 1. Trivial differences were detected between the trial arms for mean player age,stature, body mass or the distribution of players by maturity
timing (table 1).

Exposure, injury and compliance

The intervention cohort (n=17 schools, 44 teams) accrued
37 346 exposure-hours (match, 9083; training, 28 263), with thecontrol cohort (n=14 schools, 39 teams) reporting 32 375 exposure-hours (match, 6855; training, 25 520). The intervention
cohort recorded 233 match injuries (totalling 6499 days lost)and 58 training injuries (1028 days lost), with the control cohort
recording 208 match injuries (5907 days lost) and 54 training
Table 2

injuries (1150 days lost). Overall match and training injury incidence in the intervention cohort was 26/1000 hours (23–29) and2/1000 hours (2–3), and in the control cohort was 30/1000 hours(27–34) and 2/1000 hours (2–3), respectively.
Summary injury and exposure results between the trial arms
are outlined in table 2. Of 441 reported match injuries, 168
were sustained to the head/neck (intervention, 82; control, 86),
125 to the upper limb (intervention, 65; control, 60), 113 to
the lower limb (intervention, 67; control, 46) and 35 to thetrunk (intervention, 19; control, 16). Of 168 head/neck injuries, 105 were reported as concussion (intervention, 51; control,54). Match concussion incidence in the intervention group was
6/1000 hours (4–7) and in the control group was 8 (6–10).
Complete compliance data were retrieved from 63 out of
83 teams (intervention, 32 teams; control, 31 teams). In teams
who had provided complete compliance information, mean
programme completion rate across both trial arms was close

Descriptive statistics for match and training injuries across the control and intervention cohorts

Exposure-hours
Injuries
Days lost to injury
Overall match
Overall training

Intervention (n=17 schools, 44 teams)

Control (n=14 schools, 39 teams)

Match

9083

6855

Rate ratio (90% CL)–

p Value–

Training

28 26325 520

–

–

Match

233

208

–

–

Training

58

54

–

–

Match

6499

5907

–

–

Training

1028

1150

–

–

Incidence

26 (23–29)

30 (27–34)

0.85 (0.61–1.17)

0.40

Burden715 (701–730)

862 (844–880)

0.83 (0.58–1.18)

0.38

Incidence

2 (2–3)2 (2–3)0.97 (0.52–1.81)

0.94

Burden36 (34–38)

45 (43–48)

0.80 (0.40–1.60)

0.60

Incidence

9 (7–11)13 (10–15)

0.72 (0.51–1.01)

0.11

Burden260 (252–269)

285 (274–296)

0.91 (0.55–1.51)

0.77

Incidence

7 (6–9)9 (7–11)0.82 (0.51–1.31)

0.48

Burden229 (221–238)

345 (333–356)

0.66 (0.40–1.10)

0.18

Incidence

2 (1–3)

2 (1–3)0.90 (0.47–1.71)

0.78

Burden36 (32–39)

43 (38–47)

0.84 (0.35–2.01)

0.74

Incidence

7 (6–9)7 (5–8)1.10 (0.7–1.72)

0.73

Burden190 (182–197)

189 (181–198)

1.00 (0.52–1.93)

1.00

Incidence

22 (20–25)

27 (23–30)

0.85 (0.60–1.19)

0.42

Burden607 (594–621)

689 (673–706)

0.88 (0.60–1.29)

0.59

Incidence

2 (1–3)

2 (1–3)0.94 (0.50–1.77)

0.88

Burden77 (72–81)

121 (114–128)

0.63 (0.25–1.64)

0.43

Match injury by location Head/neck Upper limb
 Trunk Lower limb
Match injury by event Contact Non-contact

Incidence values presented as injuries/1000 hours. Burden values presented as days lost/1000 hours.
CL, confidence limits.

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to twice per week (intervention, 1.9 sessions/week; control,
2.0 sessions/week). Twelve out of 63 teams maintained a mean
weekly programme completion rate of three or more sessions(intervention, seven teams; control, five teams). Compliance tothe exercise programmes (proportion of programme parts thatwere completed) were 69% and 83% across the intervention andcontrol arms, respectively.

Intention-to-treat analyses

Intention-to-treat analyses on the effect of trial arm (intervention, 17 schools, 44 teams; control, 14 schools, 39 teams) were
unclear for overall match injuries (incidence RR=0.85, 90% CL:
0.61 to 1.17; burden RR=0.83, 0.58 to 1.18) (figure 2). Effects
were also unclear for contact-related injuries (incidence RR=0.85,
0.60 to 1.19; burden RR=0.88, 0.60 to 1.29). However, clear
effects favouring the intervention programme were noted forhead/neck injuries (incidence RR=0.72, 0.51 to 1.01), upper
limb injuries (burden RR=0.66, 0.40 to 1.10) and concussion(incidence RR=0.71, 0.48 to 1.05).

Per-protocol analyses

Per-protocol trial arm comparisons (intervention, four schools,
seven teams; control, three schools, five teams) revealed thatteams completing the intervention programme three times
or more per week suffered 72% fewer overall match injuries(incidence RR=0.28, 0.14 to 0.51), 72% fewer contact-related
Figure 3 Forest plot illustrating the results of the per-protocol
analyses on the effect of trial arm on injury measures in teams witha mean programme completion rate of more than three completions
per week (n=7 schools, 12 teams). Data points represent RR of injury
measures in the intervention arm relative to the control arm (referencegroup, RR=1.00). Dotted vertical lines represent thresholds for smallest
worthwhile effects (RR=0.90 and 1.11). Data labels represent the percent likelihood that each effect favours the intervention | is trivial |favours the control, for outcome variables which demonstrate a clear
effect of trial arm allocation. *Likely, ***most likely. CL, confidence
limits.

Figure 2 Forest plot detailing the results of the intention-totreat analyses for the effects of trial arm on injury measures(n=31 schools, 83 teams). Data points represent RR of injury measuresin the intervention arm relative to the control arm (reference group,
RR=1.00). Dotted vertical lines represent thresholds for smallest
worthwhile effects (RR=0.90 and 1.11). Data labels represent the percent likelihood that each effect favours the intervention | is trivial |favours the control, for outcome variables that demonstrate a clear
effect of trial arm allocation. *Likely, **very likely, ***most likely.
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injuries (incidence RR=0.28, 0.14 to 0.56), 50% fewer days lostto contact injuries (burden RR=0.50, 0.21 to 1.18), 81% fewer
upper limb injuries (incidence RR=0.19, 0.07 to 0.50), 70%
fewer lower limb injuries (incidence RR=0.30, 0.10 to 0.92)
and 59% fewer concussions (incidence RR=0.41, 0.17 to 0.99)
than teams that completed the control programme three or moretimes per week (figure 3).
Per-protocol analyses conducted in the intervention arm indicated that teams typically completing at least three sessions per
week with the intervention programme (four schools, seventeams) suffered 39% fewer match injuries (incidence RR=0.61,
0.42 to 0.88), 48% fewer days lost to match injuries (burden
RR=0.52, 0.29 to 0.93), 42% fewer match contact injuries(incidence RR=0.58, 0.41 to 0.82) and 55% fewer days lost
to match contact injuries (burden RR=0.45, 0.25 to 0.82) thanteams that completed the intervention programme fewer than
three times per week (10 schools, 25 teams). Effects of intervention programme dose were unclear for upper limb injuries, lower
limb injuries and concussion.

DISCUSSION

This study aimed to determine the efficacy of a movement
control exercise programme for preventing injury in youth
rugby players and to assess the effect of programme dose on
injury measures. Following intention-to-treat analyses, effects
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Figure 4 Forest plot illustrating the effects of intervention programme dose on injury measures (n=14 schools, 32 teams). Data points represent
RR of injury measures in teams completing >3 sessions per week relative to teams completing <3 sessions per week (RR=1.00). Dotted verticallines represent thresholds for smallest worthwhile effect (RR=0.90 and 1.11). Data labels represent the per cent likelihood that each effectfavours >3 completions per week | is trivial | favours <3 completions per week, for outcome variables which demonstrate a clear effect of programme
dose. *Likely, **very likely. CL, confidence limits.
of the trial arm were unclear for overall match injury. Per-protocol trial arm comparisons under conditions of high dose(≥3 weekly programme sessions) revealed clear reductions
for the intervention arm for overall match injury, contact-related injury, upper and lower extremity injury and concussion
incidence values. Moreover, a higher intervention programme
dose was shown to reduce the incidence and burden ofoverall match injuries and contact injuries compared withlower intervention programme doses (<3 weekly programmecompletions).

Intention-to-treat analyses

Intention-to-treat analyses indicated unclear effects of trial
arm for overall match injury (incidence RR=0.85, burden
RR=0.83) and match contact injury (incidence RR=0.85;
burden RR=0.88). The 15% reduction in overall match injury
incidence in this study is lower than the 41%–56% reductions
noted in other studies conducted in male basketball and soccer
players,8 10 11 which may be partly attributed to differences
between definitions of reportable injuries, programme content,or the distribution of injury types and locations between therespective sports, that is, proportion of non-contact lower
limb injuries. However, clear effects favouring the intervention
exercise programme were noted for head/neck injury incidence(incidence RR=0.72) and concussion incidence (incidence
RR=0.71). Sixty-two per cent of reported head/neck injuries
in the trial were attributed to concussion, and therefore thereductions in head/neck injury incidence were likely because of
reductions in concussion incidence. Concussion is a priority forprevention across contact and collision sports due to potential
concern over medium-term and long-term player welfare.29 30
Thus, the substantially reduced concussion incidence across theintervention arm is a very promising finding with regards tocurrent efforts to reduce the risk of concussion.
Neck strength has been shown to be substantially lower inadolescent rugby players when compared with adult players
despite similar peripheral strength profiles.31 Increased concussion risk is associated with lower neck strength, highlighting thischaracteristic as a potentially modifiable risk factor.12 Enhancing

neck muscle strength may prevent concussion by improving
the dissipation of impact forces transmitted to the brain.32 33
Therefore, it is possible that the neck resistance exercises in
the intervention exercise programme contributed to reduced
concussion incidence via this mechanism. Neck pain is a common
physical complaint among young sportspeople participating incollision sports34 35 and may be associated with increased concussion risk.33 Given that acute and cumulative rugby exposure canadversely impact neck function,36–38 the neck resistance exercises
may also have contributed to preserving neck function during
the playing season,39 in turn reducing concussion incidence.
Upper limb injuries are common in contact sports and can also
result in substantial time loss in youth rugby players.5 40 Teamsin the intervention trial arm suffered substantially fewer days
absence due to upper limb injuries than teams in the controlarm (burden RR=0.66). Little is known about the underlying
risk factors and mechanisms for upper limb injuries, and examples of evidence-based upper limb injury prevention are scarce.41
Reduced glenohumeral rotation and rotator cuff muscle strength
imbalances may be modifiable risk factors for shoulder injuries inrugby players.42 The intervention programme may have improved
joint kinematics and force-handling capabilities within the upper
limb as a result of incorporating resistance and plyometric training
of upper body regions,43 44 thus implying that reducing upper
limb injury risk across youth contact sports is possible throughimproving upper limb strength, stability and mobility.

Per-protocol analyses

The lack of clear substantial effects for overall match andcontact-related injuries following intention-to-treat analyses
should be considered in the context of dose, which may haveaffected these outcomes. Although mean intervention programme
dose in this study was higher (1.9 completions per week) thanhas been reported in previous studies (1.3–1.4 completions perweek),45 46 the level of dose that teams received in the intervention trial arm may have been insufficient to demonstrate aclear effect on overall match injuries. Greater effects of preventive exercise programmes may be realised if regularly used atleast three times per week.25 Trial arm comparisons conducted

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on a per-protocol basis showed that intervention trial arm
teams that regularly completed the programme more than threetimes per week suffered 72% fewer overall match injuries, 72%
fewer contact-related injuries, 81% fewer upper limb injuries,
70% fewer lower limb injuries and 59% fewer concussions
than control teams with an equivalent dose. When per-protocol
analyses were conducted within the intervention arm, teams
that regularly completed the programme over three times per
week suffered 39% fewer match injuries, 48% fewer days lost to
match injuries, 42% fewer contact injuries and 55% fewer days
lost to contact injuries than teams with less than three weekly
programme completions. Regularly performing a preventive
exercise programme three times per week over a sustained period
has been shown to improve markers for neuromuscular control
and muscle strength in male soccer players.47 Therefore, these
physiological benefits may explain the enhanced effects noted inthis study with a high dose of the intervention programme use
compared with the control programme and a lower dose of theintervention programme.
Evidence of a dose–response effect on overall and contact-related injuries in this study presents wider applications of thedose–response effect of preventive exercise programmes, andhas the potential to inform subsequent implementation attempts
through identifying a minimum effective dose in this population.
The collective findings from the intention-to-treat and per-protocol analyses highlight that teams involved in contact sports canobtain benefit from using preventive exercise programmes, butmore importantly, regular exposure of more than three times per
week can result in substantial injury risk reduction.

Limitations and future directions

There were several limitations to this study that should be
acknowledged. First, the research team members that ran the
pre-trial workshops and conducted pre-season visits were notblinded to the programme allocation for each school, creating
potential bias between the two groups in terms of the processes
followed and information disseminated at these workshops;
this was mitigated through use of a unified workshop format.
Second, individual player compliance was not monitored during
the study. Results of previous studies have indicated that individual player compliance may be a more sensitive measure thanteam compliance in determining the influence of compliance on
programme efficacy,45 46 but puts considerable strain on coaches,and so was not feasible in this setting. Third, it was not possible
to validate coach compliance reports or to monitor exercise
fidelity (the quality of performing the exercises) through unannounced visits or observations, given that schools have strict
policies around access to premises. The fidelity with which teams
used the programmes is uncertain, but may actually have mediated programme efficacy along with dose and compliance.48
Further work is required to understand the mechanistic basesby which the intervention exercise programme reduced injury
outcomes, particularly in relation to the proposed effects of the
programme on neck strength and function in reducing concussion incidence, as well as kinematics and force handling capacities
in the upper limb. Determining efficacy is a crucial step towards
effecting a public health impact of injury prevention measuresin rugby, although results of this controlled trial alone are notsufficient to translate to reducing injuries in ‘real world’contexts.49 50 Further research is required to further understand the contexts into which the exercise programme would
be implemented, as well as identifying what factors may facilitate or inhibit programme use.18 In particular, studies should
be directed to identifying what factors could facilitate or inhibit
7 of 8teams from completing the intervention programme three times
per week.

CONCLUSION

Although intention-to-treat results highlighted trivial effects of
the intervention exercise programme on overall match injury
incidence when compared with the control exercise programme,a substantial reduction in overall match injury incidence wasevident from per-protocol trial arm comparisons under conditions of high programme dose (three or more weekly sessions).
Notable beneficial effects of the preventive programme on upperand lower extremity injuries and concussion incidence also haveimportant implications for the reduction of these priority injury
types in youth rugby.

What are the findings?
►► Intention-to-treat analyses revealed that the intervention

programme substantially reduced upper limb injury burden(RR=0.66, 90% CL 0.40 to 1.10) and concussion incidence(RR=0.71, 90% CL 0.48 to 1.05) compared with the control
programme.
►► Completing the intervention programme 3 times per week
led to substantial reductions of 72% in overall matchinjury incidence (RR=0.28, 90% CL 0.14 to 0.51) and 72%
in contact-related injury incidence (RR=0.28, 90% CL
0.28 to 0.56) compared with the control programme.
How might it impact on clinical practice in the future?
►► These findings provide encouraging evidence that a

pre-activity preventive exercise programme can substantiallyreduce injury risk in youth rugby.
►► Notable reductions in upper extremity injuries andconcussion offer promising implications for the prevention ofthese high-risk injury types in young rugby players.
►► Findings also outline a minimum effective dose of three
sessions a week, whereby programme efficacy can be
optimised.
Acknowledgements The authors would like to acknowledge with sincere
gratitude all school coaches and medical staff for the recording of injury, exposureand compliance data during the study period. Furthermore, thanks are expressed
to members of the project’s ‘Technical Project Group’ who contributed to thedevelopment of both exercise programmes: Matthew Cross, Alasdair Dempsey,
Carolyn Emery, Richard Mack, Katie Morris, Simon Roberts, Des Ryan, Evert
Verhagen, Sean Williams, Shaun Williams.
Contributors GT, KAS, MEE and SK initiated the overall project. MDH, KAS, SW,
CDM, MEE, SK and GT conceived and designed the study. MDH analysed thedata and prepared the first draft of the manuscript. All authors made substantial
contributions to revision of the manuscript prior to submission.
Competing interests None declared.
Ethics approval Research Ethics Approval Committee for Health (REACH) at the
University of Bath.
Provenance and peer review Not commissioned; externally peer reviewed.
Open Access This is an Open Access article distributed in accordance with theCreative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which
permits others to distribute, remix, adapt, build upon this work non-commercially,and license their derivative works on different terms, provided the original work
is properly cited and the use is non-commercial. See: http://​creativecommons.​org/​
licenses/​by-​nc/​4.​0/© Article author(s) (or their employer(s) unless otherwise stated in the text of thearticle) 2017. All rights reserved. No commercial use is permitted unless otherwise
expressly granted.

Hislop MD, et al. Br J Sports Med 2017;51:1140–1146. doi:10.1136/bjsports-2016-097434

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Original article
REFERENCES

1 Carter M. The unknown risks of youth rugby. BMJ 2015;350:h26.
2 Pollock AM, Kirkwood G. Removing contact from school rugby will not turn children
into couch potatoes. Br J Sports Med 2016;50:963–4.
3 Tucker R, Raftery M, Verhagen E. Injury risk and a tackle ban in youth Rugby Union:
reviewing the evidence and searching for targeted, effective interventions. A criticalreview. Br J Sports Med 2016;50:921–5.
4 Archbold HA, Rankin AT, Webb M, et al. RISUS study: rugby injury surveillance inUlster schools. Br J Sports Med 2017.51.
5 Palmer-Green DS, Stokes KA, Fuller CW, et al. Match injuries in English youth
academy and schools rugby union: an epidemiological study. Am J Sports Med
2013;41:749–55.
6 Maffulli N, Longo UG, Gougoulias N, et al. Long-term health outcomes of youth sports
injuries. Br J Sports Med 2010;44:21–5.
7 Maffulli N, Longo UG, Spiezia F, et al. Sports injuries in young athletes: long-term
outcome and prevention strategies. Phys Sportsmed 2010;38:29–34.
8 Longo UG, Loppini M, Berton A, et al. The FIFA 11+ program is effective in preventing
injuries in elite male basketball players: a cluster randomized controlled trial. Am J
Sports Med 2012;40:996–1005.
9 Grooms DR, Palmer T, Onate JA, et al. Soccer-specific warm-up and lower extremity
injury rates in collegiate male soccer players. J Athl Train 2013;48:782–9.
10 Owoeye OB, Akinbo SR, Tella BA, et al. Efficacy of the FIFA 11+ warm-up programme
in male youth football: a cluster randomised controlled trial. J Sports Sci Med
2014;13:321–8.
11 Silvers-Granelli H, Mandelbaum B, Adeniji O, et al. Efficacy of the FIFA 11+
injury prevention program in the collegiate male soccer player. Am J Sports Med
2015;43:2628–37.
12 Collins CL, Fletcher EN, Fields SK, et al. Neck strength: a protective factor reducing
risk for concussion in high school sports. J Prim Prev 2014;35:309–19.
13 Brooks JH, Kemp SP. Recent trends in rugby union injuries. Clin Sports Med
2008;27:51–73.
14 Junge A, Cheung K, Edwards T, et al. Injuries in youth amateur soccer andrugby players—comparison of incidence and characteristics. Br J Sports Med
2004;38:168–72.
15 Sugimoto D, Myer GD, Micheli LJ, et al. ABCs of evidence-based anterior cruciate
ligament injury prevention strategies in female athletes. Curr Phys Med Rehabil Rep
2015;3:43–9.
16 Sugimoto D, Myer GD, Foss KD, et al. Dosage effects of neuromuscular training
intervention to reduce anterior cruciate ligament injuries in female athletes: metaand sub-group analyses. Sports Med 2014;44:551–62.
17 Sugimoto D, Myer GD, Barber Foss KD, et al. Critical components of neuromusculartraining to reduce ACL injury risk in female athletes: meta-regression analysis. Br J
Sports Med 2016;50:1259–66.
18 Finch C. A new framework for research leading to sports injury prevention. J Sci Med
Sportdiscussion 2006;9:3–9.
19 Schulz KF. CONSORT 2010 statement: updated guidelines for reporting parallel grouprandomized trials. Ann Intern Med 2010;152:726–32.
20 Hayes RJ, Bennett S. Simple sample size calculation for cluster-randomized trials. Int J
Epidemiol 1999;28:319–26.
21 Hislop MD, Stokes KA, Williams S, et al. The efficacy of a movement control exercise
programme to reduce injuries in youth rugby: a cluster randomised controlled trial.
BMJ Open Sport Exerc Med 2016;2:e000043.
22 Fuller CW, Molloy MG, Bagate C, et al. Consensus statement on injury definitions
and data collection procedures for studies of injuries in rugby union. Clin J Sport Med
2007;17:177–81.
23 Rae K, Orchard J. The Orchard Sports Injury Classification System (OSICS) version 10.
Clin J Sport Med 2007;17:201–4.
24 Hopkins WG. Generalized linear mixed models in SPSS. SportSci 2016;20.
25 Herman K, Barton C, Malliaras P, et al. The effectiveness of neuromuscular warm-up
strategies, that require no additional equipment, for preventing lower limb injuries
during sports participation: a systematic review. BMC Med 2012;10:75.

26 Hopkins WG. A spreadsheet for deriving a confidence inteval, mechanistic inference
and confidence inference from a p-value. SportSci 2007;11.
27 Hopkins WG. Linear models and effect magnitudes for research, clinical and practicalapplications. SportSci 2010;14.
28 Batterham AM, Hopkins WG. Making meaningful inferences about magnitudes. Int J
Sports Physiol Perform 2006;1:50–7.
29 Batten J, White AJ, Anderson E, et al. From management to prevention: the new curefor sports concussion. Br J Sports Med 2016:50:1293–4.
30 Benson BW, McIntosh AS, Maddocks D, et al. What are the most effective riskreduction strategies in sport concussion? Br J Sports Med 2013;47:321–6.
31 Hamilton DF, Gatherer D, Robson J, et al. Comparative cervical profiles of adultand under-18 front-row rugby players: implications for playing policy. BMJ Open
2014;4:e004975.
32 Patel DR, Shivdasani V, Baker RJ. Management of sport-related concussion in young
athletes. Sports Med 2005;35:671–84.
33 Schneider KJ, Meeuwisse WH, Kang J, et al. Preseason reports of neck pain, dizziness,and headache as risk factors for concussion in male youth ice hockey players. Clin J
Sport Med 2013;23:267–72.
34 Schneider KJ, Emery CA, Kang J, et al. Examining sport concussion assessment tool
ratings for male and female youth hockey players with and without a history of
concussion. Br J Sports Med 2010;44:1112–7.
35 Shehata N, Wiley JP, Richea S, et al. Sport concussion assessment tool: baseline values
for varsity collision sport athletes. Br J Sports Med 2009;43:730–4.
36 Lark SD, McCarthy P. The effects of a rugby playing season on cervical range of
motion. J Sports Sci 2010;28:649–55.
37 Lark SD, McCarthy PW. Cervical range of motion and proprioception in rugby players
versus non-rugby players. J Sports Sci 2007;25:887–94.
38 Lark SD, McCarthy PW. The effects of a single game of rugby on active cervical rangeof motion. J Sports Sci 2009;27:491–7.
39 Maconi F, Venturelli M, Limonta E, et al. Effects of a 12-week neck muscles training
on muscle function and perceived level of muscle soreness in amateur rugby players.
Sport Sci Health 2016;12:443–52.
40 Bleakley C, Tully M, O’Connor S. Epidemiology of adolescent rugby injuries: asystematic review. J Athl Train 2011;46:555–65.
41 Steffen K, Andersen TE, Krosshaug T, et al. ECSS position statement 2009: preventionof acute sports injuries. Eur J Sport Sci 2010;10:223–36.
42 Ogaki R, Takemura M, Iwai K, et al. Risk factors for shoulder injury in collegiate Rugby
union players. Inter J Sport Health Sci 2014;12:31–7.
43 Andersson SH, Bahr R, Clarsen B, et al. Preventing overuse shoulder injuries among
throwing athletes: a cluster-randomised controlled trial in 660 elite handball players.
Br J Sports Med 2016.
44 Niederbracht Y, Shim AL, Sloniger MA, et al. Effects of a shoulder injury prevention
strength training program on eccentric external rotator muscle strength andglenohumeral joint imbalance in female overhead activity athletes. J Strength Cond
Res 2008;22:140–5.
45 Soligard T, Nilstad A, Steffen K, et al. Compliance with a comprehensive warm-up
programme to prevent injuries in youth football. Br J Sports Med 2010;44:787–93.
46 Hägglund M, Atroshi I, Wagner P, et al. Superior compliance with a neuromusculartraining programme is associated with fewer ACL injuries and fewer acute knee
injuries in female adolescent football players: secondary analysis of an RCT. Br J Sports
Med 2013;47:974–9.
47 Impellizzeri FM, Bizzini M, Dvorak J, et al. Physiological and performance responses to
the FIFA 11+ (part 2): a randomised controlled trial on the training effects. J Sports Sci
2013;31:1491–502.
48 Fortington LV, Donaldson A, Lathlean T, et al. When ‘just doing it’ is not enough:assessing the fidelity of player performance of an injury prevention exercise program.
J Sci Med Sport 2015;18:272–7.
49 Hanson D, Allegrante JP, Sleet DA, et al. Research alone is not sufficient to prevent
sports injury. Br J Sports Med 2014;48:682–4.
50 Twomey D, Finch C, Roediger E, et al. Preventing lower limb injuries: is the latest
evidence being translated into the football field? J Sci Med Sport 2009;12:452–6.

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8 of 8

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Reducing musculoskeletal injury andconcussion risk in schoolboy rugby playerswith a pre-activity movement control exercise
programme: a cluster randomised controlled
trial
Michael D Hislop, Keith A Stokes, Sean Williams, Carly D McKay, Mike E
England, Simon P T Kemp and Grant Trewartha
Br J Sports Med 2017 51: 1140-1146 originally published online May 17,2017doi: 10.1136/bjsports-2016-097434
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