Muscle Medicine: The Revolutionary Approach to Maintaining, Strengthening, and Repairing Your Muscles and Joints (3 page)

The lowest blow of all is that aging recreational athletes who maintain their cardiovascular fitness on the running trail, the tennis court, or in the gym are probably more susceptible to musculoskeletal damage than their couch-potato counterparts. (Ever notice how many social gatherings and dinner parties turn into a litany of “war wounds”?)

Muscle Medicine
is a manual about fighting back: how to make the right choices to address both healthy and damaged muscle, whether it’s on your own or with professional care. It lays out the first truly integrative approach to the care and repair of muscle and joint problems. Whether you’re an accomplished athlete, you want to maintain your regular tennis routine, or you just want to be able to play with your kids, or your grandkids, without back pain after a long day at the office, we want to be on your team.

Dr. DeStefano

Every day, I treat patients who are convinced that the source of their pain is the damage inside their joint that shows up on an X-ray or MRI. A patient will come in and say, “Can you help me with my meniscus tear in my knee?” I’ll say, “No, I can’t help you with the meniscus tear, but I may be able to help you with the pain in your knee.” What people don’t usually understand is that in many cases, if we can get the muscles around the joint to move properly, the joint itself doesn’t have to be in perfect shape for the system to work without pain. That’s something I can appreciate. I’ve been in two serious accidents—once when a car hit me while I was training for the Ironman World Championships and once in a Manhattan cab crash—and I’ve got the chipped vertebrae and herniated disks to show for it. A year ago, the pain in my back and neck flared up so badly, my orthopedist was ready to bring in a neurosurgeon to work me up for disk surgery. I kept exercising, getting manual therapy, and applying self-treatment. Slowly, over a month, the contracted muscles in my cervical and lumbar spine let go their grip, and the pain went away. I’m not cured; I still have damaged disks. I may need surgery down the line, but as long as I’m symptom-free and maintain the health of my muscles, I’m fine.

PART 1 YOUR BODY

These next two chapters will introduce you to the biology of your musculoskeletal system. In
chapter 2
, “How the System Works,” you’ll learn about the basic building blocks of the system— muscles, bones, and joints. In
chapter 3
, “System Malfunction,” you’ll be exposed to the major forces, internal and external, that can tear the system down.

HOW THE SYSTEM WORKS: MUSCLES, BONES, JOINTS

Before
we talk about lifestyle issues or jump into the nuts and bolts of body problems, let’s first admire the machinery and come to a basic understanding of how it works. As we’ve said, muscles and bones and joints form one integrated system, and no one component is more important than another. Without muscles, you would be a motionless pile of bones; without a skeleton, you’d look and move more like a jellyfish; and without joints to control and stabilize the bones, you’d stumble around like the scarecrow from the
Wizard of Oz
.

MUSCLES

The muscles under your conscious control—skeletal muscles—are the motors that drive the human system. (The smooth muscle that lines the organs and the cardiac muscle that keeps your heart beating are involuntary.) The muscles function in tandem. As one muscle shortens it exerts a pulling force, while at the same time its
counterpart relaxes. This simultaneous action of a contracting
agonist
muscle and a relaxing
antagonist
muscle powers all the movements of the body. That’s the case whether it’s a sprinter thrusting his lead leg forward (the massive quadriceps muscles in the front of the thigh contracting, the hamstrings in back relaxing) or you bending your finger to scratch your nose (flexor digitorum contracts, extensor digitorum relaxes).

Controlling the movements of so many muscles is precision work that is initiated and coordinated in the brain. The process might seem as simple as turning on a light switch, but in reality, it’s a constant neurochemical conversation between the nerves and the muscles. That is, the brain oversees the production of specific chemicals that activate the muscles. What happens is this: the brain sends a chemical message to the motor neurons in the spinal cord which then deliver that message to the target muscle, telling it what to do. Sensory nerves gather information about the current status of that part of the body and send that information back up the spinal cord to the brain for processing. Some information is so basic, it doesn’t need to be processed by the brain: it travels only from the muscles to the spinal cord and back, in a feedback loop called a “reflex arc.” For example, the muscles have reflexes that prevent them from overstretching or overcontracting, or that jerk your hand off a hot stove before you even register pain.

A more complex conversation between the muscles, nerves, and brain is called “proprioception”—knowing where your body is in space. It allows you to run and jump and navigate the world without falling (usually) or even thinking much about it. When you’re injured, that conversation is disrupted. Not only do the muscle tissues have to heal, but the lines of communication between the muscle and the brain have to be reestablished so you can run or swing a golf club or play a note on the violin with your brain on “automatic pilot.”

But it’s how muscles interact with each other and the rest of the body that most concerns us here. Muscle is dense with capillaries that feed it with the blood— carrying oxygen and nutrients—that it needs to do its work. We may think of the football player with big muscles as rugged and tough, but the muscle tissue itself is surprisingly delicate, made up mostly of water. (They don’t call it soft tissue for nothing.) The body is closely packed with overlapping muscles that must move smoothly against each other if humans are to move with any fluidity.

From micro to macro, the master plan is steady, unimpeded motion—movement
is life. Not only do neighboring muscles need to slide against each other, so do the fiber bundles inside the individual muscles, and so again, the tiny myofibrils inside the fibers. We can see what muscular contraction looks like at the most basic molecular level only with an electron microscope: two types of protein filaments inside the myofibrils, actin and myosin, pulling against each other.

The defining aspect of the muscle is the muscle “belly,” where most of the muscular force is generated. Fortunately, nature has outfitted the muscle with tough connective tissue at both ends, the tendons, where the muscle attaches to the bone. The tendons transmit muscular force and actually pull on the bones. Remember, regular muscle tissue can’t even hold a surgeon’s stitch, much less control a bone in motion. (Our word
muscle
comes from the Latin word for mouse,
mus
. The cord- or band-shaped tendons were thought to resemble the snout and the tail of a mouse!)

Another element of the muscle package is the fascia, the thin, tough, translucent membrane that weaves around everything in the body: muscles, bones, organs, nerves, the works. You could visualize it as the casing around the meat in a string of sausages. Or take a close look at an uncooked chicken or slab of beef. It’s the white covering around the muscle that runs through it and around it. In the body (human, cow, or chicken), fascia serves as a kind of flexible internal skeleton, holding the muscles in place, but also moving with them, and helping them slide over neighboring structures.

BONES

You take for granted that your muscles are a living, dynamic system. Work out in the gym even for just a few weeks and you’ll see the strength and, depending on the amount of testosterone circulating in your system, the size of your muscles increase. (Inside the muscles, the numbers of capillaries increase, pumping up
the fluid content; new protein—the building block of muscle—is laid down; the mitochondria—the power plants inside the cells—increase in density.)

The skeleton might seem rather inert, by comparison, a convenient frame to which muscles and organs are attached. True, after you stop growing in your teens or early twenties, your bones don’t get any longer. But your skeleton is a system as alive as any other in the body. About a third of bone is made up of living cells. Inside the bone, marrow cells are producing red and white blood cells, as well as other cells that help drive the immune system.

The outside of the bone is covered by a fibrous membrane, the periosteum, which contains blood vessels and nerves. (When you break a bone, it’s the ruptured periosteum that causes the pain.) But even the two-thirds of the bone made up of hard mineral (mostly calcium phosphate) isn’t static. Bone is always slowly but constantly being reshaped. Special cells called osteoclasts eat away at old or damaged bone. This activity is balanced by that of the osteoblast cells, which create new bone. Bone is reabsorbed where it is not needed and laid down where it is. As overall bone density drops significantly in the senior years (those osteoclasts gain the upper hand in the end), it’s up to you to stress the system in healthful ways (i.e., activate the osteoblasts by lifting weights, or walking) so that it stays resilient enough to handle the bumps of everyday life. In other words, use it or lose it.

JOINTS

Movement happens when muscles generate the force to move the bones. But we need a third component, a simple mechanism that allows bones to articulate, to move against each other, so that actual work—lifting, lowering, etc.—can occur. We call these mechanisms joints. Let’s take the simple action of lifting your forearm. The top end of the biceps muscle attaches in the shoulder area; this is the muscle’s
origin,
its stable, anchoring point. The other end of the muscle attaches to the moving bone at the
insertion,
in this case, just below the elbow joint. Anchored at the shoulder, the biceps muscle contracts, lifting up the forearm. The biceps is the agonist muscle, and when it fires, the antagonist muscle, the triceps, releases. A muscle can only pull as it contracts. It’s got no “push” mode, which is why muscles have to work together. When it’s time for that forearm to lower, the triceps, now the agonist, contracts, and the biceps, now the antagonist, relaxes, and the deed is done.

Most of the joints we’ll be talking about in this book function as lever systems. In other words, the joint translates the individual efforts of a number of muscles into a decisive, coordinated movement of the limbs. The knee and the elbow are hinges that only allow movement in one or two directions; the ankle and the wrist allow more freedom of movement. The hip and the shoulder are ball-in-socket joints with the greatest range. Every joint makes its own trade-off between strength, stability, and range of motion.

The joint’s purpose is to provide the bones with the maximum movement, the necessary stability, and a minimum of friction. The bones that form the joint fit into a sleeve called a joint capsule, which is filled with lubricating synovial fluid. The ends of the bones inside the capsule are covered with smooth articular cartilage that allows them to move against each other without grinding. Finally, outside the joint, synovial-fluid-filled sacs called bursas provide an extra measure of musculoskeletal cushioning.