Now that the Chicago White Sox have swept the Houston Astros in the World Series, most baseball players are taking some time to rest. Time off is especially important for pitchers because throwing a baseball overhand is an unnatural motion and a burden on the shoulder and the elbow.
Now a research team led by WUSTL sports medicine specialists has found that professional pitchers have significantly decreased range of motion in their throwing elbows.
The researchers reported on a study of 33 professional baseball pitchers in the October issue of the American Journal of Sports Medicine. Trainers and team doctors measured the pitchers’ ability to bend, straighten and rotate their elbows and found that range of motion in the dominant elbow was limited when compared to the other arm.
“On average, pitchers had an 8 degree loss of the ability to straighten their elbow when compared to the elbow in their non-dominant arm,” said first author Rick W. Wright, M.D., assistant professor of orthopaedic surgery and co-director of the Division of Sports Medicine at the School of Medicine and Barnes-Jewish Hospital.
“But despite the fact that they lose range of motion, we’ve been unable to show that there’s a functional impact.”
The pitchers in the study not only couldn’t straighten their arm as far, called extension, they also had difficulty bending the elbow (flexion). A pitcher’s dominant elbow bent about 5 degrees less than the elbow in his other arm.
But the study found no significant difference in the ability of the elbow to rotate (supination and pronation).
Wright, the head team physician for the St. Louis Cardinals, said it’s unclear how the losses in range of motion occur.
“Once we looked at all of the data and did the statistical analysis, we could not find a correlation between increased age, innings pitched or injuries,” he said. “We could not find anything that explained why range of motion was inhibited in the pitching elbow.”
That was a surprise.
Although it’s not clear why the losses in range of motion occur, Wright said it is clear that the loss is not enough to hurt a pitcher’s ability to perform on the mound.
He said even with the losses in motion, most pitchers are still flexible enough to throw a baseball effectively. He added that the losses in motion should not have a negative impact on normal daily activities outside of baseball.
It’s likely that professional pitchers start with strong, flexible elbows that can take high amounts of stress, qualities that helped get them to the pro level, Wright said.
“By the time they reach this level, a lot of people have been eliminated who didn’t have elbows that could stand up to these stresses,” he said. “These players definitely have shown that their elbows are made for pitching.”
But not right now. With the World Series in the rear-view mirror and spring training still months away, he said sensible pitchers are resting their elbows.
“At this time of year, I recommend that pitchers shut it down as far as throwing a baseball,” Wright said. “They need this time to rest and to work on basic strengthening and stretching.
“In December or January, they’ll restart a throwing program with the goal of being ready when spring training begins.”