Referred pain from the lower back
Pain into the the hip and thigh can often be associated with referred pain from the lower back and one of the most common reasons is because of trapped nerves.
Sometimes this can also be due to joint pain from either the lower back or sacroiliac joints. In this case the characteristics of the pain will often be different in nature. Joint pain in the lower back usually manifests itself as a sharper, short-lived pain generated by movement, which transfers to the buttock or upper thigh. Sacroiliac pain often refers to the upper buttock and groin.
Each vertebra in the spine has numbers as you can see in the diagram. In the lower back or lumbar spine, the vertebrae are numbered L1 to L5. Slipped, herniated or disc bulges or protrusions usually occur at the bottom your lower back at L3, L4 or L5 where nerves exit, and these are numbered S1-S5.
The discs at the bottom of your lower back (L3/L4, L4/L5 and L5/S1) are the levels most likely to suffer from trapped nerves because these areas help support most of the weight of your upper body (two thirds of your total body weight). The sciatic nerve runs from the bottom three vertebra as seen below and innervates the area around your hip, the back of the thigh and lower leg and foot.
If a nerve is trapped at L2 or L3 or L4 this will affect the femoral nerve (as seen below) and we suffer from femoral nerve impingement which provides both feeling and power to the front of the thigh. Therefore we experience pain in this specific anatomy.
These conditions cause a characteristic pain distribution down the leg. The areas of skin a single nerve innervates in the leg is called a dermatome. Each specific nerve will be responsible for sensory perception in a very specific area of skin (sensory perception being temperature, touch, vibration, pressure and pain). Therefore if a nerve is impinged in the lower back, pain and pins and needles (or paraesthesia) will refer to any given dermatome.
So sciatic pain will potentially refer to any of those areas innervated from L3 to S3 levels (these levels innervate the back of the leg) and femoral nerve impingement will cause pain L2-L4 levels (these dermatomes innervate the front of the thigh) which provide both feeling and power to the front of the thigh.
Things to be aware of that are clinically significant and indicate that you need to take further action when you have sciatica are:
- Severe impingement can weakness in the ankle when walking (known as foot drop)
- Progressive leg weakness
- In extreme cases loss of bowel or bladder control and tingling/ numbness in groin area indicates a possible medical emergency.
For the femoral nerve, this nerve generally provides both feeling and power to the front of the thigh (it innervates what we call the hip flexors and knee extensors). Movements such as climbing stairs (the knee may unstable and prone to buckling) will be difficult as your thigh muscles will feel weak. Pain may also be felt on the side of the buttock, groin, inside of the knee and lower leg.
It is also worth mentioning that all the muscles in the legs are also innervated by nerves from different levels in the spine as well. These are called myotomes. The sciatic nerve for example will carry nerves for both sensory and motor innervation (motor as in ‘motor power’). The information you give us in clinic and our clinical testing will help establish at which level in your spine you have a trapped nerve.
Our new IDD Therapy programme is effective in treating trapped nerves, is non-invasive (unlike surgery) and is pain-free. IDD Therapy bridges the gap between what manual therapy cannot achieve and surgery. This therapy is the fastest growing therapy for trapped nerves and degenerative disc issues in the UK.
Referred pain from the knee
Pain can also be generated from the kneecap (patella) and this can result in thigh pain. It is also important to remember that any instability or trauma to significant structures in the knee can also cause referred pain into the thigh as well.
Examples would be ligament, muscle or meniscal injuries or osteoarthritis of knee joint or indeed any damage to the fibula in the lower leg.