PT  - JOURNAL ARTICLE
AU  - M Møller
AU  - R O Nielsen
AU  - J Attermann
AU  - N Wedderkopp
AU  - M Lind
AU  - H Sørensen
AU  - G Myklebust
TI  - Handball load and shoulder injury rate: a 31-week cohort study of 679 elite youth handball players
AID  - 10.1136/bjsports-2016-096927
DP  - 2017 Feb 01
TA  - British Journal of Sports Medicine
PG  - 231--237
VI  - 51
IP  - 4
4099  - http://bjsm.bmj.com/content/51/4/231.short
4100  - http://bjsm.bmj.com/content/51/4/231.full
SO  - Br J Sports Med2017 Feb 01; 51
AB  - Background Knowledge of injury patterns, an essential step towards injury prevention, is lacking in youth handball.Aim To investigate if an increase in handball load is associated with increased shoulder injury rates compared with a minor increase or decrease, and if an association is influenced by scapular control, isometric shoulder strength or glenohumeral range of motion (ROM).Methods 679 players (14–18 years) provided weekly reports on shoulder injury and handball load (training and competition hours) over 31 weeks using the SMS, phone and medical examination system. Handball load in a given week was categorised into (1) <20% increase or decrease (reference), (2) increase between 20% and 60% and (3) increase >60% relative to the weekly average amount of handball load the preceding 4 weeks. Assessment of shoulder isometric rotational and abduction strength, ROM and scapular control was performed at baseline and midseason.Results An increase in handball load by >60% was associated with greater shoulder injury rate (HR 1.91; 95% CI 1.00 to 3.70, p=0.05) compared with the reference group. The effect of an increase in handball load between 20% and 60% was exacerbated among players with reduced external rotational strength (HR 4.0; 95% CI 1.1 to 15.2, p=0.04) or scapular dyskinesis (HR 4.8; 95% CI 1.3 to 18.3, p=0.02). Reduced external rotational strength exacerbated the effect of an increase above 60% (HR 4.2; 95% CI 1.4 to 12.8, p=0.01).Conclusions A large increase in weekly handball load increases the shoulder injury rate in elite youth handball players; particularly, in the presence of reduced external rotational strength or scapular dyskinesis.