Results

There were no baseline or starting differences between players in the intervention and control groups for age and hamstring and knee injury history—important because these are the main risk factors for new injury. Results were:

a. Lower Limb Muscle Strain. Those in the intervention group and receiving chiropractic care had a statistically significant reduced risk of injury—injury rates were 3.6% in the intervention group and 27.6% in the control group. This had a large impact on missed matches. There were only 4 missed matches for lower limb muscle strain for the 28 players in the intervention group who completed the trial, 21 missed matches for the 29 in the control group.

b. Hamstring Injuries. There was a similar trend, but this did not reach the level of statistical significance. The incidence of injury in the intervention group was again 3.6% with 4 matches missed, compared with 17.2% in the control group with 14 matches missed.

c. Non-Contact Knee Injury. Incidence of injury in the intervention group was 3.6%, in the control group 24.1% There was a statistically significant difference in the number of matches missed—1 in the intervention group, 24 in the control group.

d. Adverse Reactions. No player reported an adverse reaction to the intervention/chiropractic care.

e. Low-Back Pain. On the McGill Pain Questionnaire at baseline and at midpoint of the season there was a statistically significant reduction in overall and current back pain in the intervention group and current back pain in the intervention group but not the control group.

f. Health Status. At the mid season on the SF-39 health status questionnaire there was statistically significant improvement on various measures only for those in the intervention group—on the measures of bodily pain, role limitations due to physical health, general health and physical summary score.

Hoskins and Pollard emphasize that most of the chiropractic treatment was not directed to the hamstring areas, and that the results suggest that a variety of non-local factors amenable to multidisciplinary management appear to contribute to hamstring and other lower limb injuries. Their findings, they conclude “are important due to their potential for injury reduction, performance benefit and cost-saving practices for a relatively low-cost intervention.

Summary

The authors suggest that the most significant difference between treatment offered to the intervention and control groups was the quantity and range of HVLA manipulation. The physiotherapy manual therapy … will principally have been joint mobilization and soft-tissue therapy.

A major impact of the HVLA manipulation is likely improved neuromuscular control of the lumbopelvic region, creating improved function of the hamstrings—changes to existing length-tension and force-velocity relationships of the hamstrings that provide risk of injury.

There is much greater use of chiropractors in professional football in the U.S. Currently all 32 teams in the National Football League (NFL) have team chiropractors who belong to the Professional Football Chiropractic Society (www.profootballchiros.com). Hall of Famer Jerry Rice is a national spokesperson for the profession. Internationally many elite football clubs, such as Chelsea in the UK and AC Milan in Italy, now have team chiropractors. Skiers and skaters at the Winter Olympics, and sprinters and gymnasts at the Summer Olympics are attended by chiropractors.

When sprinter Donovan Bailey won the 100 meters in world record time at the Atlanta Olympic Games his first comment in the post race television interview was one of thanks to his chiropractor for keeping him injury free. However the road to even greater awareness and acceptance of the contributions chiropractic care can make must be paved with good quality research—congratulations to Hoskins and Pollard for their fine and continuing contribution.

David Chapman-Smith is Secretary General of the World Federation of Chiropractic and Editor of The Chiropractic Report.