Preparticipation evaluation and identification of aetiological risk factors in the epidemiology of sports injuries among youths

Abstract

In a preliminary study the incidence and nature of sports injuries among 483 primary school children was observed prospectively. A total of 76 injuries were incurred. Netball had a significantly higher (p<0, 05) injury incidence (injuries per player-hours) than hockey (1:16,4 vs 1:61,6) and soccer had a significantly lower (p<0,001) incidence than rugby ( 1: 2 0, 6 vs 1: 6, 6) . No injuries ocurred among tennis players. Ligament sprains (42%) and contusions (41%) predominated and most injuries occurred in the lower extremity (48%), followed by the head, neck and trunk collectively (30%). The primary study focussed on the preparticipation evaluation and identification of aetiological risk factors for injury among a cohort (N=125) of high school rugby players. Notable health history findings among subjects were syncope with exercise (1,3%); problematic paired organs (10,3%); familial heart disease (15,4%); concussion (21,8%); and previous musculoskeletal injury (61,5%) which was the most significant (p<0,05) and frequent problem experienced. Medical examination detected problems with the cardiovascular (7,7%), urinary (9,0%); and orthopaedic systems (33,3%) respectively with the last component having the highest diagnostic utility ( 62%) in yielding new findings not reported in the history. As an adjunct, subjects were screened for morphological status and muscular function. The prevalence of obesity (8%) was noted. Ipsilateral and contralateral imbalances in peak isokinetic (60° /s) torque of the quadriceps/hamstring musculature were recorded. Dominant-limb absolute (Nm) quadriceps (Q) vs hamstring (H) torque results for asymptomatic subjects (n=70) stratified by age were: 13 yrs - 100,0 ± 29,8 vs 76,9 ± 20,8; 14 yrs - 134,2 ± 29,8 vs 93,0 ± 21,7; 15 yrs - 156,8 ± 37,4 vs 109,5 ± 28,5; 16 yrs - 162,3 ± 24,2 vs 116,8 ± 23,0; 17 yrs - 223,6 ± 46,0 vs 142,6 ± 28,3. Relative (Nm/kg) quadricep and hamstring torques were: 13 yrs - 1,98 ± 0,23 vs 1,50 ± 0,08; 14 yrs - 2,32 ± 0,30 vs 1,63 ± 0,23; 15 yrs - 2,44 ± 0,38 vs 1,70 ± 0,30; 16 yrs - 2,50 ± 0,22 vs 1,80 ± 0,20; 17 yrs - 2,87 ± 0,39 vs 1,85 ± 0,22. H/Q ratios were: 13 yrs - 77,7 ± 6,0%; 14 yrs - 69,9 ± 9,6% and 15-17 yrs - 68,1 ± 9,0%. The final preparticipation evaluation disposition led to clearanc,9 being withheld from 6,4% of the players, pending referral for additional evaluation, with the remainder being granted unlimited participation. A total of 171 injuries were recorded prospectively as sustained by 76 players over the 14 weeks injury surveillance phase of the season. This resulted in an overall injury incidence of 1: 21 player-hours. When considering only those injuries resulting in a loss of at least seven days participation (major injuries), a significantly lower (p<0,01) incidence of 1:212 player-hours was recorded. In the extrinsic risk factor analysis, significantly more overall (84%;p<0,001) and major (82%;p<O,Ol) injuries occurred during matches than in practices. The overall injury incidence (injuries/ 100 player-hours) was lowest in the under-14 age group ( 3, 6) , while the under-19 11 A 11 ( 1st team) players ( 5, 2) were particularly injury prone. The highest overall ( 34, 0) and major (5,7) weekly injury incidence was observed during the four weeks fallowing the Easter vacation. Players were injured significantly more (p<0,001) during various facets of broken play (92%) than the set-pieces (8%) of scrums (7%) and line-outs (1%). Both the overall and major injury risk was greatest whilst being tackled (30 & 35%) and during open play (23 & 29%), while tackling (24%) was particularly conducive to major injury. The playing positions at highest overall and major injury risk were flyhalf (16 & 24%) and fullback (13 & 16%) while flank (16%) and wing (12%) were prone to major injury. The significant majority (98,8%;p<0,001) of injuries were acute in nature with the predominant (86%) injury mechanism being contact/collision. The lower-limbs were at significantly greater (p<0,05) overall (42%) and major (41%) injury risk. Osseous contusions were the commonest overall injury (32%) while muscle injuries, each), fractures and concussion (18% prevalent major injuries.