Prior to 2017, Tigers slugger Jose Cabrera had a baseball swing kids and big leaguers alike wanted to emulate. His batting average was higher than .310 in eight consecutive seasons, from 2009-16, and led the American League in four of those seasons. Then, in 2017, it was painful to watch Cabrera struggle to a .249 mark. But not nearly as painful as it was for Cabrera to swing the bat.
In late September, the 34-year-old Cabrera, who had dealt with pain since the World Baseball Classic in March, was diagnosed with two herniated disks in his lumbar spine, between his L3 and L4, and L4 and L5 vertebrae. Then, he finally opened up about the back, hip and leg pain that had been plaguing him all season.
"This has bothered me since Spring Training," he said in September. "It's been bothering me all year. At some points I was feeling good, and at some points I feel I can't go anymore. I need to change a lot of things this [offseason] so I can come in better shape."
Cabrera went on to explain how his pain had caused him to alter his swing, using his hips less and his arms more, resulting in less-than-ideal mechanics -- and performance -- at the plate.
"I'm leaning back. There's no way you're going to hit like that," Cabrera said. "I think this year I struck out with a lot of bad swings on a lot of pitches out of the strike zone. But the good thing is I know what I'm doing wrong."
The radiating pain Cabrera felt in his hips and legs is called radicular pain, or nerve-root pain, resulting from the pressure his herniated disks are putting on his spinal cord. His lack of explosion is the result of a neurological deficit caused by that same pressure. It's scary. It feels like it would threaten a career. But with proper care and a little luck, it won't.

First, consider this. As high as 35 percent of lumbar disk herniations in elite professional athletes occur in baseball players, because the axial rotation of the spine during hitting and pitching is considerably higher than it is in other sports. If you're looking at a hitter from above, axial trunk rotation is the amount the shoulders rotate in relation to the hips.
For some comparison, according to a 2012 study done by Dr. Glenn Fleisig and colleagues at the American Sports Medicine Institute in Birmingham, Ala., baseball hitters get an average of 46 degrees of trunk rotation. Pitchers get 55 degrees, while a tennis forehand produces just 30 degrees of rotation. The force with which an athlete reaches that level of rotation is also important, but it is not possible to measure accurately. Still, it is safe to assume that Cabrera, at 6-foot-4 and 240 pounds, generates quite a bit of force.
"Isaac Newton tells us that force equals mass times acceleration," Fleisig said. "It takes more force to move more mass, so while Cabrera may get the same trunk rotation as a smaller guy, it requires more force for him to do it."
And that force is absorbed by Cabrera's spine.

The spine is made up of rings of bone, or vertebrae, that are stacked on top of each other and encase and protect the spinal cord. They are separated by disks that serve as shock absorbers and allow motion. Because of those cushions, the spine is built to withstand tremendous amounts of compressive force. But rotational forces are a different story, which is why Cabrera felt so much pain trying to rotate his hips through his swing.
"Disks do much better with compression, with bending forward or extending," said spine specialist Dr. Andrew Cordover, of Andrews Sports Medicine & Orthopaedic Center in Birmingham. "But baseball is a rotational sport. You're twisting, and the lumbar disks do not stand up well to rotational forces."
Think of each disk as a jelly donut. The outer layer of the donut, or the annulus fibrosis, is composed of collagen tissue similar to ankle and knee ligaments. The inner part -- the jelly -- is the nucleus pulposus, composed mainly of water and collagen fibers.

"The annulus, which does not do well with torsion, can tear, and the nucleus pulposus can herniate, or pop out," Cordover says. "A herniated nucleus pulposus can put pressure on the nerves and cause radicular, or nerve pain, or sciatica from the lower back into the legs."
When a disk is herniated, the body can recognize the disk fragment pushing through the annulus as potentially harmful material, just as it would recognize and fight bacteria. The body's immune system can employ macrophages -- white blood cells that destroy pathogens and rid the body of debris annulus fibrosis -- to break down the disk material until it can be reabsorbed by the body. In time, the annular tears can also heal.
"I've seen this happen in two or three weeks, and I've seen it happen in six months," Cordover said.
While the body is doing its work to heal, doctors have several options to treat patients with herniated disks, including oral anti-inflammatories, muscle relaxers or pain medications, and epidural or nerve-block injections, which simply address the patient's pain so they can allow the spine to heal. Physical therapy will be utilized to strengthen and stabilize the core, lower back and hips, and to address any specific weaknesses or neurological deficits caused by the herniated disks. Cabrera, who has been adamant about not getting an injection that will only mask his pain, opted for six weeks of physical therapy to begin this offseason.
"I don't want to get an injection, because I don't want to put a Band-Aid on my injury," Cabrera said. "I can't just put a Band-Aid on it and say, 'I don't have the injury now.' There is no reason to do that."
The good news for Cabrera is that, according to a 2010 study, baseball players with herniated disks have greater than a 95 percent return-to-play rate, and those who elect to undergo non-operative treatment have slightly longer careers post-injury than those who choose to have surgery.
"We've got to learn from this," Cabrera said. "This season has given me nightmares. But I need to sit back and think about it and learn from it. See what I do bad and what I can do better to have a better season next year."