2019 Boca Juniors’ Fabiana Vallejos in action REUTERS/Agustin Marcarian TPX IMAGES OF THE DAY
Spring has sprung in the Northern Hemisphere while the mild days of fall are starting in the Southern. With the change in the weather, young athletes everywhere are getting out and playing footie. Meanwhile, coaches scrambling for best practices to give their team the edge often resort to technical training. Chilean researchers have just released a study that may have coaches rethinking all those cone drills.
These sports scientists wondered if plyometric jump training would enhance predictable measures of strength as well as carryover and improve other skills unrelated to the jumping exercise(1). To measure the effects of drop jump (DJ) training, they divided 39 male competitive youth soccer players into a control group (CG) and a DJ group. The average age of the subjects was 13.2 years. The study was conducted mid season so that all participants were currently playing at the same level.
The CG continued with their regularly scheduled training practices twice per week. The DJ group swapped their usual technical training for DJ training during their twice-weekly practice. The protocol consisted of three sets of 10 reps of 20-cm and 40-cm drop jumps for seven weeks. The athletes rested between reps for 15-seconds for the 20-cm jumps and 90-seconds for the 40-cm jumps. All jump sessions were monitored to ensure correct technique and athletes were encouraged to achieve their highest possible jump with the smallest possible amount of ground contact between the drop and the jump.
Various measurements of ability were conducted both before and after the intervention. They included:
Multiple 5 bounds test
5-rep max test with a parallel squat at maximal load
Illinois change of direction speed test
Maximum kick distance
2400-meter time trial
The researchers found that the DJ group showed significant within-group improvement after the DJ training intervention in all areas measured except the 20-meter sprint. Within the CG, the post-testing revealed significant improvement in only the 5-rep max test after the 7 weeks, and a significant decrease in the 20-meter sprint and change of direction performances. When comparing the two groups post-intervention assessments, the improvements within the DJ group were significantly better than those of the CG with the exception of the 5-rep max in which there was no significant difference.
Implications for injury recovery
You may be wondering why these findings may be important to rehabilitation professionals. Despite the fact that this study was done on young athletes, it tells us something about the transference effect of certain exercises. A transference effect occurs when gains are made in an untrained exercise as a result of an unrelated exercise. An example of this is when strength gains are made in a contralateral limb despite never having exercised that side. In other words, will the explosive training and neuromuscular changes induced by drop jumps improve other measures of explosive movement? This study seems to support that it does. Therefore, while technical drills have their value, would rehabilitation time be better spent on activities such as the drop jump?
While all test subjects in this study were healthy young males, should physios consider activities with proven crossover benefits as part of the rehab course for injured athletes? Would the overall gains be greater and the time in rehab spent more efficiently? This study doesn’t answer those questions, but it leads us to consider the rehab activities we recommend and how well these activities train athletes to meet the benchmarks set for return-to-play readiness.
Change of direction is vital for athletic performance. However, the high injury risk requires athletes to have the appropriate technical and physical capacities. Helen Bayne discusses the demands of direction changes in sports and identifies key movement patterns for practitioners to address during lower limb injury prevention and rehabilitation. Atlanta Falcons wide receiver Drake London... MORE
Concussion research continues to gain the support of sports medicine professionals. However, many remain in the dark regarding the potential of rehabilitation to improve clinical outcomes. Megyn Robertson shines a light on vestibular and oculomotor rehabilitation following concussion. Football – Premier League – Aston Villa’s John McGinn receives medical attention before being replaced by a... MORE
Experiencing pain is a fundamental biopsychosocial phenomenon. However, practitioners typically treat pain in isolation with little emphasis on psychological influence. Carl Bescoby explores the psychological impact of pain and discusses how psychologically informed practice may offer benefits to managing the whole pain experience throughout rehabilitation. Introduction It is common for athletes to experience pain when... MORE
Researchers obtain qualitative data through first-hand observation, interviews, questionnaires, and other non-numerical sources of information. Jason Tee explores how clinicians can utilize the qualitative data and the athlete’s voice to improve rehabilitation outcomes. Sports injury research is clinical, impartial, and objective. It reduces athlete injuries to numbers and figures, removing the stories of the athletes... MORE
Artificial playing surfaces are contentious and remain a talking point in Sports and Exercise Medicine. Marianke van der Merwe uncovers the artificial surface injury risk and provides recommendations to mitigate the risk factors for athletes. Artificial turf was first introduced in the 1960s and has evolved significantly. There are three reasons for artificial turf. Firstly,... MORE
Menopause is the natural end of a female’s menstrual cycle and can have profound and diverse effects on women. Tracy Ward discusses how the female athlete can adapt and continue to train through the menopausal transition. Menopause is the natural end of a female’s menstrual cycle, and clinicians define it as 12 months after the... MORE