Jan 29, 2015
Bulletin Board

Better Predictions

When an athlete is injured, one of the first questions coaches ask is, “How long will they be out?” With hamstring injuries, athletic trainers don’t typically have an answer. However, a recent study has highlighted a way to use MRI images to forecast a return-to-play timetable. Led by James Bradley, MD, MS, the Head Orthopedic Surgeon for the Pittsburgh Steelers, and John Norwig, ATC, MEd, the team’s Head Athletic Trainer, the study evaluated 57 MRIs of hamstring injuries suffered by 43 NFL players, uncovering several factors that played a role in determining recovery time. From there, the researchers categorized recovery time frames into three groups. The first category includes mild hamstring injuries that allow an athlete’s return in seven days or less. The MRI generally shows that less than 50 percent of the cross-sectional area of the hamstring is involved in the injury, that it occurs in a single muscle, and that the trauma is located in a proximal or mid-muscle tendon junction. Additionally, no circumferential edema or retraction of the hamstring is found. Moderate injuries are placed in the second group, with a return-to-play prediction of seven to 16 days. These injuries cover more than 50 percent of the cross-sectional area of the hamstring and most involve more than one muscle. They tend to be distal, and circumferential edema is frequently discovered. Lastly, the most severe injuries comprise the third group, with a return-to-play time frame of 21 days or more. Any retraction of the hamstring or cyst formation in the muscle should immediately place a player into this category. Bradley and Norwig also found that an extended recovery period is needed when MRIs show more than 75 percent of the cross-sectional area of the muscle is involved in the injury. While the research did not indicate any reason to change the rehab process for hamstring injuries, Bradley and Norwig’s predictor system might keep sports medicine professionals from sending an athlete back too soon. “The number one risk factor of hamstring injury is a prior hamstring injury,” says Bradley. “With this system, if an athletic trainer looks at a hamstring MRI and sees retraction and cyst formation, they’ll know that player should be out for at least 21 days.”

Which First?

Cardio and weight training are staples of most strength and conditioning programs, and research has shown that the benefits of each increase when they are incorporated into the same training session. But does the order matter when it comes to maximizing gains? Two recent studies say no. Part of a broader series of investigations into the subject conducted by the Department of Biology of Physical Activity at the University of Jyväskylä, Finland, both studies used the same protocol to evaluate a group of 42 recreationally active men ages 18 to 40. For each examination, the participants performed endurance (incremental stationary bike test) and strength (dynamic leg press) activities two or three times a week for 24 weeks. In the first study, 16 of the men executed an endurance-before-strength (E+S) sequence, while 18 did the reverse order (S+E). Of those who completed the second trial, 12 men did E+S and 17 performed S+E. The first investigation, published in the February 2014 issue of Medicine & Science in Sports & Exercise, found that time to exhaustion, aerobic power, total lean mass, muscle cross-sectional area, and one-repetition maximum all increased significantly in both groups over 24 weeks. However, there were no significant differences in the results between the E+S and S+E groups. In the second study, which can be found in the April 2014 issue of the European Journal of Applied Physiology, the E+S and S+E groups showed no dissimilarities when it came to changes in acute reductions of force, recovery of force, and concentrations of growth hormone. The E+S participants experienced reduced concentrations of testosterone for up to two days following recovery in week zero, but this difference diminished through the 24 weeks of training and did not appear to correlate with any strength gains.

To read an abstract of “Fitness and lean mass increases during combined training independent of loading order” or “The order effect of combined endurance and strength loading on force and hormone responses: effects of prolonged training,” search for either title at: pubmed.gov.

Tommy John Results

There’s no doubt ulnar collateral ligament reconstruction (UCL) surgery has extended the careers of thousands of baseball pitchers in the 40 years since Tommy John was the first to undergo the procedure that carries his name. The question of whether it improved their performance, however, has been the subject of ongoing debate. While some pitchers have anecdotally reported the surgery enhanced their success, new research has found that major league pitchers who undergo the procedure rarely return to their pre-injury performance levels.

Researchers at Henry Ford Hospital looked at 168 major league pitchers who underwent Tommy John surgery between 1982 and 2010. These athletes were age-matched to 178 pitchers with no prior UCL reconstruction and their performance statistics three years prior to and following the surgery were analyzed.

The study, presented in March 2014 at the annual meeting of the American Academy of Orthopaedic Surgeons in New Orleans, found that in the second and third season prior to their surgery, members of the Tommy John group had “significantly better” statistics than the non-surgery group in ERA, walks plus hits allowed per inning pitched (WHIP), and innings pitched. However, the performances of the injured group declined significantly in the season immediately preceding the surgery. When looking at data for the first three seasons after the injured players returned to the mound, the results were drastically different. In categories where a difference was observed, the average statistics of the control group were better, and the surgery group saw their average ERA and WHIP increase from 4.15 to 4.74 and 1.40 to 1.48, respectively. In addition, the average number of innings pitched in the surgery group dropped from 59 to 50.

Vitamin D2 Can Cause Damage

While some athletes and powerlifters believe vitamin D2 has performance-enhancing properties, new research shows it may actually have a negative effect. Researchers from Appalachian State University found that athletes who supplemented heavily with vitamin D2–also known as ergocalciferol–experienced greater muscle damage following intense workouts than those who received a placebo.

In the study, which was published in the January 2014 issue of the journal Nutrients, 28 NASCAR pit crew members underwent baseline testing in a series of exercises that included a bodyweight bench press to exhaustion and a vertical jump. The athletes then had their blood drawn to provide a baseline for their serum vitamin D status and were questioned about the amount of delayed onset muscle soreness (DOMS) they felt. Next, they were randomly divided into two groups, with 13 athletes consuming 3,800 IUs of a plant-based vitamin D2 supplement daily for six weeks and the other 15 ingesting a placebo during the same time frame. When the six weeks concluded, the athletes went through a 90-minute eccentric workout composed of 17 different activities. Their blood was drawn before, immediately afterward, and again at 24 and 48 hours post-workout. The blood was tested for serum vitamin D and muscle damage biomarkers, and the athletes were also asked about their DOMS at each stage. Researchers found that, based on the biomarkers, the group that took the vitamin D2 supplement experienced more muscle damage following the eccentric workout than the placebo group.

To view the full text of the study, search “Vitamin D2 Supplementation Amplifies Eccentric Exercise-Induced Muscle Damage in NASCAR Pit Crew Athletes,” at: mdpi.com.


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