BRINGING SCIENCE TO TREATMENT
With 14% of United States runners preferring to train on an motorized treadmill (MT), many clinicians using the MT as a tool in gait-retraining, and its role in the collection of sports science data, it is important to understand the differences between running on an MT and overground(1). A group from the Netherlands wondered what the body of research had to say about these different modes of running. They conducted a systematic review and meta-analysis of the current studies to compare the biomechanical differences between running on the ground and a level (non-inclined) MT(1).
After an exhaustive search, they arrived at 33 published articles that met inclusion criteria for the study. The total population was 494 subjects, roughly two-thirds of which were male. The studies compared various biomechanical and spatiotemporal aspects of running on the MT versus overground; however, they varied drastically in the measured parameters and reported findings. While individual studies may have reported significance in their measurements, this usually didn’t present as significant in all of them, resulting in low-grade evidence for the conclusions (see figure 1). Therefore it appears that running on a treadmill is quite similar to running overground.
“Summary of significant differences between treadmill and overground running biomechanics found with meta-analyses. Overall surface effects are indicated in black, subgroup (individual surface) effects in gray. Amplitude of muscle activity represents a qualitative interpretation of the findings as meta-analysis could not be performed for this outcome. ROM range of motion. Treadmill; “down arrow” lower; “up arrow”, greater/longer compared to overground.” Sports Med. 2019 Dec 4. doi: 10.1007/s40279-019-01237-z. [Epub ahead of print]
So what are the implications of this review? Firstly, the type of MT used matters. While the equipment may appear similar, differences exist in the rate of belt turnover, the width of the belt, the stiffness of the belt, and the power of the motor. Know your machine and understand how its mechanics impact the runner. For instance, it appears from the study that a more powerful motor translates to longer stride times by the runner. While a wider belt means that an athlete’s stride times might be shorter than if they were running on the concrete. A stiffer running surface provided by the MT might also change biomechanics as the body compensates by increasing knee flexion and ankle dorsiflexion at footstrike.
Secondly, minute changes may occur when running on a treadmill, such as a decrease in vertical displacement and a change in muscle activation. Additionally, the study emphasizes the fact that familiarity with the MT impacts performance. Therefore, when analyzing a runner’s gait, it is best to allow them to get comfortable running on the treadmill for at least eight minutes before examining their biomechanical patterns(1).
Furthermore, the researchers cite a study completed after the search period of the meta-analysis that showed an increase in muscle forces in the gastroc/soleus complex while running on an MT(1). For those with Achilles tendon or calf injuries, running on an MT might not be the best place to begin after rehab. They also report that running on an MT may decrease running economy and require more energy from the runner.
in Diagnose & Treat, Email Newsletters, Knee injuries
Adolescence is often a period of rapid growth for most children. Because bones grow faster than muscles, this growth can lead to tension from the tendons at their insertion on the bone, causing an apophysitis. One of the most difficult-to-treat conditions related to such growth is Osgood-Schlatter Disease (OSD), an apophysitis at the tibial tuberosity.... MORE
More women are playing soccer than ever before. In fact, the rate of females joining soccer teams is outpacing the growth of all other sports(1). Injuries from playing soccer are on the rise as well. According to the NCAA, injuries occurred in collegiate female soccer players between 2004 and 2009, at a rate of 7.3... MORE
in Email Newsletters, Knee injuries
Knee injuries are the bane of athletes in nearly all sports (see figure 1)(1). Clinicians and sports scientists continue to explore the best way to prevent such injuries. The knee, a hinge joint, moves in the sagittal plane. The thought is that most knee injuries occur from forced movement in the frontal plane. Therefore, control... MORE
in Improve, Prevent, Tools and technology
Jason Tee explains the challenges of returning young athletes to sport safely and efficiently and provides practical guidelines for keeping them injury-free. Many nations are starting to ease strict lockdown rules, allowing life to return to normal after the novel coronavirus pandemic. Professional sportspeople and weekend warriors alike are chomping at the bit to get... MORE
The NCAA reported that there were 81,096 black college athletes during the 2018-2019 academic year(1). These numbers represent 16% of the college athlete population(1). The majority of these athletes play men’s and women’s basketball and men’s football. Of course, many of these go on to play in professional sports. The number of high-school and younger... MORE
All therapists like to think that they provide the magic touch that gets their patients better. However, when considering all social determinants of health, the influence of medical interventions toward recovery from musculoskeletal injury is only 20%(1). You put your best effort into helping patients get better, but your effectiveness is up against other competing... MORE
