By Carrie McCulloch

Carrie McCulloch is a 4th-year medical student at the Mount Sinai School of Medicine, a Certifying Instructor for Pilates Academy International, and Course Co-Director for the Functional Anatomy for Movement & Injuries (FAMI) Workshop.

Degenerated discs, prolapsed discs, bulging discs, herniated discs—these terms float around Pilates studios quite freely. Indeed, these conditions are some of the most common reasons why clients with back pain seek help from Pilates instructors in the first place. Despite their familiarity, however, these terms—and the medical jargon surrounding them—can get quite confusing. Here, I’ll explain the particulars of three common disc problems and suggest programming tips for affected clients.

ANATOMY REFRESHER
Before delving into what goes wrong with discs, it’s best to start with a general anatomical review of what they are and do, when functioning properly.

The Intervertebral Disc
Commonly likened to a jelly doughnut, an intervertebral (IV) disc has two layers: an inner gelatinous mass (the nucleus pulposus), and an outer fibrous casing (the annulus fibrosis). The content of the nucleus pulposus is mostly water, affording it the ability to act as a modified hydraulic shock absorber every time the spine moves. The water composition, however, decreases with age, and contributes to the progressive decrease of one’s height over time. The tougher annulus fibrosis surrounds the inner pulposus with fibrocartilagenous concentric layers, increasing the disc’s shock absorption capability. In addition to shock absorption, the two components of the IV disc work together to provide intervertebral stability and an axis of rotation for spinal movement.

So what happens when our discs go south? What causes the problem, exactly, and what causes the pain? Here’s a look at three common disc injury scenarios:

DEGENERATIVE DISC DISEASE

What is it?
As mentioned above, as bodies age, so do their intervertebral discs: the nucleus pulposus dries out and loses its shock-absorbing abilities, while the annulus fibrosis becomes brittle and subject to tears. Whether we like it or not, these changes seem to be part of the spine’s normal aging process. In many people, this process goes unnoticed; in others, it causes back pain, the condition known as Degenerative Disc Disease (DDD) and a host of other consequences.

According to the working theory of DDD, which is based on studies of the lumbar spine, the aging process can provoke a pathologic cascade of events. Put as simply as possible, as a disc begins to tear and dysfunction, instability and inflammation ensue, and the spine attempts to compensate by producing more bone in the form of spurs (also called osteophytes). These changes occur on a continuum and can lead to other problems such as arthritis, disc herniations and spinal stenosis.

What causes the pain?
Some controversy surrounds the exact cause of pain in DDD. Current theories point to the interplay of the following factors: the disc’s own nerve supply, inflammation and microinstability. Part of the annulus fibrosis has many nerves running through it, and small tears, or inflammation caused by irritants within the nucleus pulposus, can be painful. This type of pain is known as discogenic as it arises from the disc itself, and is usually described as “aching.” In addition, as a disc deteriorates and contributes to microinstability, nearby muscles pick up the slack and provoke painful spasms.

The pain from DDD is usually localized to the site of injury, most commonly in the lumbar or cervical spines, and can be referred to other places in the body, such as the buttocks and posterior thighs. DDD pain, however, is often inseparable from other co-existing degenerative problems, such as disc herniations, that add their own assortment of aches and pains to the body.

DISC BULGE & DISC HERNIATION
What are they?
In addition to degenerating, discs are also infamous for bulging, herniating, protruding, prolapsing and a litany of other terms. Confused by the nomenclature? You’re not alone. A few years ago, it took an entire multidisciplinary task force of spine specialists to come up with recommendations for a universal vocabulary. Here’s a slimmed-down synopsis of their semantics:

Basically, there are two general scenarios that happen when a disc (or some part of it) is displaced from its intervertebral home. First, a disc bulge refers to a generalized outpouching of a disc’s outer edges—i.e., the whole disc appears swollen—that may result from a variety of reasons, both normal and abnormal. In contrast, a disc herniation is defined as a localized displacement—i.e., a focal protrusion—of disc material. In most cases, the disc’s nucleus pulposus is the protruding culprit; it peeps through a tear in the annulus fibrosis and often herniates into the vertebral canal where the spinal cord and nerves reside.

The rest of the terms, then, are regarded as either colloquial synonyms for a disc herniation (e.g. slipped, ruptured and prolapsed) or further classifications of its appearance. For example, a herniation can be called contained (if housed within the outer edges of the annulus fibrosis) or uncontained (if extended beyond the annulus fibrosis). It can also be categorized as protruded, extruded or sequestrated depending on its shape and location. [For images associated with the above terms, click here.]

Both disc herniations and bulges are commonly found in the lumbar and cervical spines and can either be symptomatic or silent.

What causes the pain?
Like DDD, symptomatic disc bulges and herniations can cause localized pain. The purported mechanisms are fairly similar as well: The disc and surrounding ligaments “hurt” from tearing or increased pressure, and if the contents within the nucleus pulposus escape to irritate nearby tissues, inflammation and painful localized muscle spasms can arise.
Here’s the difference: If a herniated disc impinges upon a nearby spinal nerve root (called a radicle), an affected individual can develop the pain of a radiculopathy. Unlike the deep, aching mechanical pain of back spasms, radicular pain is often described as burning, sharp-shooting and electrical. It also appears in a particular pattern, determined by a nerve’s dermatome (the circumscribed area of skin it supplies). This is why an individual with an impinged L5 spinal nerve root may experience radicular pain along the lateral aspect of the calf. In addition to pain, an impinged nerve may also cause patterns of weakness and numbness in the extremities.

PROGRAMING TIPS: Helping clients with disc problems
First, advise a client with back pain to seek medical attention and clearance—when at all possible, speak to the client’s physician and physical therapist to help get everyone on the same page.

Once you have the green light, the next step is to open your anatomy book, your eyes and your ears. While it’s easy to follow broad-sweeping dos and don’ts, the best rehab programming comes from combining your knowledge of anatomy and the client’s injury, your assessment of your client’s postural pitfalls, and your client’s feedback. To be sure, every client’s experience with disc injuries will differ, as will their response to movement. Some clients will find relief in spinal flexion, for example, while others will enjoy extension. In the end, following guidelines can be helpful—and some are recommended below—but don’t forget to listen to your own mind and your client’s body in the process.

Dos:
• Exercises to gently strengthen the spinal flexors

Example: Simple Toe Taps using the arc barrel to help stabilize the pelvis in a posterior tilt and prevent lumbar extension. Cue your client to perform the exercise slowly, with the movement coming from the hip, not the knee.

• Exercises to gently strengthen the spinal extensors

Example: Breast Stroke Preps using the arc barrel. Your client should be lying prone over the barrel, with their hips at or just behind the apex. Cue your client to perform the exercise with either a neutral or flexed lumbar spine, whichever is more comfortable.

• Exercises to gently increase range of motion of the spine

Example: Seated Spine Twist on a chair or stability ball, keeping the pelvis in neutral.

• Gentle stretches for the spinal extensors

Examples: Child’s Pose, or simple stretches, such as lying supine hugging the knees or prone over a ladder barrel.

• Tips to promote proper sitting and standing postures

Example: Teach your client how to maintain a neutral pelvis while sitting, using a stability ball.

• Tips to promote proper lifting techniques

Example: Teach your client how to reduce stress on their lumbar spine while lifting by cueing them to: 1) place themselves directly in front of the object to be lifted, 2) bend at the knees and not the waist, and 3) avoid twisting the spine while lifting or carrying something.

Don’ts:
Exercises that combine flexion and rotation or exert a downward, twisting pressure on the spine (e.g., Corkscrew or Twist with Round Back on the short box) are generally contraindicated for clients with disc injuries. Refrain from using any type of exercise that causes the client to experience radiating pain from their back into their extremities.

Please note: The information contained within this article is intended solely for the education of the reader. It is not to be used as a substitute for medical diagnosis, advice or treatment.