90% of all injuries sustained by professional golfers involve the neck or back. Low back pain is the number one injury sustained by golfers, accounting for up to 34.5% of all injuries. The average injury lasts between 2 and 4 weeks and most golfers report back pain developing over time, rather than from one traumatic incident. The impact and follow-through phase of the golf swing account for the most injuries when compared to other phases.
Source: Sports Health, July/August 2013 and Sports Health, November/December 2011