Table 1

Characteristics of included studies

Study Study design Sample and/or sport Number/rate of CMSI or ‘lower leg’ Risk factors Specific outcome Length of tracking
Bengtsson et al (2013)7 Prospective cohort27 European professional football (soccer) teams from 10 countries—621 individual playersCMSI RR=1.13/1000 hours match exposureMatch load, between match recovery, match characteristicsAcute calf muscle injury diagnosed and recorded on electronic injury registry by club medical staff11 seasons
Brooks and Kemp (2011)10 Prospective cohort899 players from 14 English Premiership rugby union clubsNAPlaying position, match-related injuryAcute calf muscle strain injury diagnosed and reported by club medical staff4 seasons
Hägglund et al (2013)8 Prospective cohort1401 players from 26 soccer clubs across 10 countriesCMSI (n=306)Previous calf muscle injury, previous other muscle injuries, age, stature, body mass, playing positionAcute calf muscle injury as diagnosed by club medical staff2001–2010 seasons
Orchard et al (2014)11 Prospective cohort1607 elite Australian Rules football playersCMSI (n=140)Age, height, weight, BMI, month, environmental conditions, calf injury within 8 weeks, previous calf injury beyond 8 weeks, older players (age>23), past quadriceps injury beyond 8 weeksCalf strain injury assessment and diagnosis by club medical staff, with or without imaging investigations1992–1999 competition seasons
Carling et al (2015)14 Prospective observational25 professional soccer players from one clubCalf IRR=4.1/1000 hours match exposureFixture congestion and match characteristicsCalf muscle injury as diagnosed and recorded by club6 seasons (2009–2015)
Nilstad et al (2014)23 Prospective cohort173 elite female Norwegian soccer players from 12 teams‘Leg/foot’ injuries
Previous knee injury, age, BMI, lower extremity strength, dynamic balance, knee biomechanics and laxity, foot posture (pronation)Calf injuries (as captured leg/foot injury data)1 season
McKay et al (2001)25 Prospective cohortElite and recreational Australian basketball players—190 players‘Calf/anterior leg’ injuries
Gender, level of competitionCalf muscle injury (as captured in ‘Calf/Anterior Leg' injuries data)2 seasons
Faude et al (2006)22 Prospective cohort143 German national league soccer players over 12 teams‘Lower leg’ injuries (n=19)Anthropometric measurements, playing position, injury history, training and match exposure timeCalf muscle injury (as captured in ‘lower leg’ data pool)1 season
Korkia et al (1994)13 Prospective study155 British triathletes‘Lower leg’ injuries
Training history, injury historyCalf muscle injuries (as reported in ‘lower leg’ injury) as self-reported questionnaire1 season
Gabbett and Domrow (2007)24 Prospective cohort183 subelite rugby league players‘Thigh and calf’ injuries 41.3/1000 hoursTraining load and injury data according to competition phasesCalf muscle injury (as described in combined ‘Thigh and Calf’ data)2 seasons
  • BMI, body mass index; CMSI, calf muscle strain injury; IRR, injury rate ratio; NA, not applicable; RR, rate ratio.