Why do I have pain down the back of my leg?

What is the Sciatic Nerve? 

In order to understand sciatica, we must first have an understanding of the structure that’s affected – the sciatic nerve. The sciatic nerve is the thickest and longest nerve in the body. It starts at the spine, travels through the hip and buttock, down the back of the leg, and splits just below the knee to form nerves of the lower leg and foot. Each lower extremity has its own sciatic nerve, which is responsible for muscle function of the hamstrings, adductor magnus, and branches of the lower leg muscles. The nerve also supplies sensation to the lateral aspect of the leg, heel, and both the upper and lower surface of the foot. Understanding the course of the sciatic nerve can help us better understand the symptoms that arise with sciatica. Identifying where your specific symptoms start and end can help to determine the source of nerve irritation. 

What is Sciatica?  

Sciatica is an umbrella term that describes the symptoms or pain that result from an irritated or inflamed sciatic nerve. While sciatica is commonly thought to include lower back pain, symptoms can actually arise anywhere along the course of the sciatic nerve including the buttock, leg, calf, and foot. Pain is usually caused by an irritation of the nerve (typically at the level of your buttock), or the nerve roots in your lower back which gives rise to the sciatic nerve. Sciatica typically affects one leg at a time and can result in symptoms such as altered sensation, tingling, numbness, burning, and muscle weakness. These symptoms can be aggravated by coughing or sneezing, moving from sitting to standing, prolonged sitting, standing or lying down. 

Sciatica is one of the most common problems we see in physical therapy, as it can occur at any age and fitness level. While it can feel like an overused or generic term, the diagnosis helps us understand that the structure causing your symptoms is the sciatic nerve. Although identifying the affected structure is important, a thorough physical therapy examination is needed to diagnose the reason for the sciatic nerve irritation. 

What Causes Sciatica?  

While nerves don’t contract and relax like muscles, nerves will function optimally when they are able to move easily through the different structures they course through. This means when there is injury, damage, swelling, or tightness from surrounding structures, the nerve can get compressed and irritated. Typically, sciatica develops over a longer period of time – it can be influenced by any of the following: 

• Spine Changes: There is a variety of changes at the spine that can occur and may lead to sciatica. These changes can include disc herniation, disc degeneration, spinal stenosis (narrowing of spinal canal), spondylolisthesis (slipping of one vertebra on another), and more. These can all lead to changes in force distribution along the spine and cause increased pressure or irritation to the surrounding structures and nerves – including the sciatic nerve. 
• Muscular Tightness: When muscles are tight, they can compress the nerves that course through them. A common site for compression of the sciatic nerve is where it passes under the piriformis muscle near the glutes. Tightness of this muscle can compress the nerve and lead to pain, numbness, tingling, or other symptoms in the buttocks and down the leg. Muscle tightness can be caused by overuse, but often it is actually caused by inactivity. While stretching and mobility are great to incorporate in your day to day, participating in a well-rounded strengthening routine is just as important. 
• Work Conditions: Heavier labor jobs that involve heavy lifting or repetitive bending over can cause irritation to the sciatic nerve if proper mechanics and strength are lacking. On the other hand, jobs that require prolonged sitting and inactivity can also cause stiffness in the spine, or muscle tightness and weakness leading to compression on the sciatic nerve.  It’s important that we develop a good baseline level of strength, give ourselves breaks throughout the day to stretch and change positions, and use safe lifting mechanics in order to prevent injury and potential irritation to the nerve. 
• Pregnancy: Sciatica can often be experienced in pregnancy. This is due to relatively rapid weight gain. This change in weight due to a growing baby causes our center of mass to change, and thus our posture changes in order to maintain balance and stability. The postural changes observed in pregnancy can cause increased pressure on the lower back and therefore lead to irritation of the nerve. Implementing mobility and strengthening routines even while pregnant can be helpful for minimizing or preventing irritation on the sciatic nerve. 

How Can Physical Therapy Help Sciatica?  

• Pain Relief and Mobility: Sciatica treatment in the early stages involves a strong focus on reducing your pain with manual therapy, dry needling, gentle nerve stretching, and spinal mobility work to reduce the sensitivity of the irritated nerve. This can yield great relief and a significant reduction in symptoms within a few visits. However, the goal of physical therapy is to ensure long term results and minimize the chance for symptoms to return. There’s a structured, yet personalized, approach to ensuring we address sciatica properly. Getting you pain-free is our first priority, but it’s our attention to detail in helping you rehabilitate through the entire journey that ensures positive results. 
• Strengthening: With moderate to severe sciatica symptoms, once your pain resolves sometimes there’s residual weakness that makes your usual tasks harder than they’d normally be. To get back to your normal self, this needs to be addressed. One major tenant of treating sciatica is strengthening exercises that target the muscles that support your lower back, buttocks, and core. This is vital, as it will contribute to your body being able to cope with the demands placed on it day to day, as well as any recreational activities you love to do. A robust long term management plan also involves targeted nerve mobility exercises to improve the movement of your affected nerves, as well as spinal mobility exercises to improve the movement of your spine.  
• Education: Ultimately, we as physical therapists want to empower you to understand your body better and ways to improve your symptoms in the long term. Throughout the course of treatment, we’ll provide advice and education on positioning, posturing, and the level of activity suitable for you to allow your symptoms to settle and keep you comfortable whilst our treatment is having the desired effect. We’ll also give you the knowledge you need to gradually build back up to the activity level you want in a safe and non-detrimental way. By the end of our treatment, we hope you have the knowledge and confidence to move forward and participate in the activities that are most meaningful to you. 

Check out our YouTube video on Sciatica here: