Have you ever experienced a sudden weakness in your leg? Have you felt you are unable to lift leg while lying down? Have you felt a pricking pain when trying to put on your pants?
Leg weakness and pain can stem from something as simple as a muscle cramp to more severe nerve issues requiring urgent medical attention. It is essential to know the difference between the two prompt interventions and care to ensure optimum recovery.
Voluntary muscle contractions are usually initiated when your brain sends a signal through your spinal cord and nerves to a group of muscles. These muscles then contract, resulting in movements such as lifting your leg or bending down. Any problem in this pathway directly or indirectly can affect the movements.
Table of Content
- 1 Common Causes of Leg Weakness and Pain
- 2 Musculoskeletal Injury: Unable to lift leg while lying down
- 3 What are the muscles responsible for lifting the leg?
- 4 Symptoms of muscle strain or injury in your legs include
- 5 How do we confirm the cause of leg weakness and pain?
- 6 Treatment
- 7 FAQ
- 8 Endnote
Common Causes of Leg Weakness and Pain
Weakness and pain in your lower limbs most often result from wear and tear, injuries, or inactivity. Sometimes, problems in your lower spine may also have an impact on your legs. The common causes of leg weakness and pain can be categorized into:
- Nerve Injury
- Muscle Injury
- Neuromuscular system dysfunction involves both the nervous system as well as the musculoskeletal system.
To find out which of the above is causing your pain, you will need to know the associated underlying conditions that may cause the respective problems.
A complex network of nerves works in coordination with your brain to initiate movement. Damage to these nerves results from various conditions that can present themselves in different ways.
Presentation of nerve injury
When the function of your nerves is disrupted, you are likely to be unable to lift leg while lying down. This occurs because the nerves cannot carry the correct signals from the brain to the spinal cord. Nerve injury can present in the following ways:
- Pricking pains in your legs or feet
- Muscle weakness
- Numbness or tingling in the legs and feet
- Feeling your leg is being compressed
- Frequent falls or loss of balance
- A buzzing sensation that feels like a mild electrical shock
Nerve damage tends to be worse in the injured body but can cause discomfort in areas surrounding it.
What causes nerve injury?
Many conditions can cause nerve injury. A few common causes are listed below.
Nerve entrapment (or nerve compression syndrome) occurs when nerves become compressed due to excess pressure surrounding them. It can happen due to a variety of reasons such as:
- Herniated disc
- Repetitive activities
- Poor posture
- Medical conditions (rheumatoid arthritis, diabetes, hypothyroidism, obesity)
A trapped nerve does not receive enough blood flow. This causes structural changes, swelling to the surrounding tissues, and damage to the nerves’ insulation. As a result, the nerves malfunction resulting in pain, paresthesia (loss of sensation), and in severe cases, paralysis.
Nerve entrapment that affects the legs is often termed lumbar radiculopathy or sciatica. Sciatica is one of the most typical causes of pain and weakness in your leg. It refers to pain along the sciatic nerve, which runs from your pelvis (lower back), through your hips and buttocks, and down each leg.
Peripheral nerves connect nerves from your brain and spinal cord to other parts of your body. Damage to peripheral nerves can be due to:
- An injury from a fall or strenuous activities that are capable of stretching or tearing your nerves
- An underlying medical condition such as diabetic neuropathy
- Autoimmune diseases such as lupus or rheumatoid arthritis
Peripheral neuropathy, as its name suggests, occurs at the peripheries. You may start developing numbness and loss of sensation in your extremities, such as your fingers or toes, before it spreads to your arms and legs.
Related: Why Do My Ears Ring When I Lay Down?
Guillain-Barre syndrome is a condition whereby the body’s defense system mistakenly attacks its nerves. Subsequently, it leads to nerve inflammation resulting in pain, weakness, and paralysis.
This is a severe condition that requires prompt treatment as the symptoms can quickly worsen. It is a treatable condition, and most people make a full recovery with proper medication and care.
Falling under the category of autoimmune disease, this condition presents various symptoms that vary significantly from person to person.
Its symptoms include limb weakness, difficulty speaking and swallowing, drooping eyelids, double vision, and shortness of breath. A cure for this disease has not been found; however, you can manage its symptoms.
Musculoskeletal Injury: Unable to lift leg while lying down
Another important cause of why you are unable to lift leg while lying down is due to injury in the musculoskeletal system, which constitutes:
- Connective tissue
Muscle weakness occurs when your total effort doesn’t produce an expected movement. Do not panic if you suddenly experience a loss of strength in your muscles. Nearly everyone experiences short-term muscle weakness at some point in time.
A heavy workout session at the gym, for example, can result in muscle exhaustion leading to a temporary muscle weakness until you’ve rested enough to give them a chance to recover.
However, if you develop persistent muscle weakness or muscle weakness with no apparent cause, it may be a sign of an underlying health condition that you should look into.
Pain, though it might feel different from weakness, may also result from muscle exertion or strain. Athletes, especially those involved in strenuous sports such as running, football, kickboxing, and martial arts, are prone to muscle injuries. The main muscles affected are the group of muscles responsible for lifting your leg.
What are the muscles responsible for lifting the leg?
The main groups of muscles responsible for enabling you to raise your leg and bend at the waist are found in the pelvic region, at the front top part of the thighs, and connect the lower back to the hips, groin, and thigh bones. They include:
- Hip flexors including Iliopsoas, sartorius, pectineus, tensor fascia lata, rectus femoris, adductor longus, and adductor brevis
- Quadriceps (thigh muscles)
- Hamstring muscles
- Rectus abdominis and obliques. These muscles are not directly involved in raising your leg but function to stabilize your pelvis and hips.
Any injury or strain to the muscles above may cause pain and weakness in your leg, making you unable to lift your leg while sitting or lying down. Apart from that, injury to these muscles may also cause lower back or hip pain, affect your posture and disrupt your walking ability.
Symptoms of muscle strain or injury in your legs include
- Weakness of legs
- Prickling pain and tenderness even at rest
- Muscle spasms
- Cramping of muscles surrounding the injury
- Swelling around the injured area
- Inability to use the muscle
How do we confirm the cause of leg weakness and pain?
Your doctor or healthcare personnel will usually start assessing you using the least invasive tests before resorting to more specialized modalities to confirm their suspicions. Some of the tests they might do are:
- Straight leg raise test– A physical examination where you are assessed on your ability to lift your legs without causing pain to your legs or back
- A complete neurological assessment to elicit the loss of power or sensation in your limbs and also to rule out any neurological disorder
- Creatine kinase test, which involves measuring the level of creatinine kinase in your body. This is an enzyme that is released from an inflamed or damaged muscle
- Electromyography is used to measure how well your muscle responds to nerve signals
- Magnetic Resonance Imaging (MRI) allows the physician to see any tears or injuries to muscles or any structural lesions that may be compressing your nerves
- Muscle biopsy in which a sample of your muscle tissue is obtained. Later, it is tested in a laboratory to diagnose any muscle pathology
Once diagnosed, the causes behind being unable to lift leg while lying down are treated accordingly. Minor injuries are usually treated conservatively, allowing the body to restore its nerve and muscle function naturally.
Repairing a nerve injury
If conservative measures prove unsuccessful, doctors recommend surgical interventions to repair a nerve injury, relieve pressure, and restore strength.
Most nerve injuries can be repaired if caught early. Waiting too long can cause them to reach a point of being irreparable. Hence, it is crucial to seek medical attention when the first signs of nerve injury are noticed.
Repairing these nerves constitutes exploring the damaged nerves and removing any injured tissues. Severed nerves can also be reconnected if there is enough space to reattach them without making them too tight.
Once the nerve has been repaired, you can expect a gradual return of full function and sensation within a few months. If improved the right way, your nerves can heal and regenerate. Sometimes, nerves that are only partially damaged can even heal by themselves.
Treating a strained muscle
You can easily treat a simple muscle strain at home. Here are some ways to help you recover quickly from a muscle injury:
- Resting the muscle is essential to expedite the healing process
- Cast or splint to protect the muscle from any further injury
- Pain medication such as nonsteroidal anti-inflammatory drugs (NSAIDs) or analgesics can help relieve pain
- A cold compress may help reduce swelling and inflammation at the site of injury
- Massage helps increase blood flow to the injured area, which promotes healing
- Gentle physical exercises may help boost muscle strength and healing
A mild strain usually heals within 3 to 6 weeks with rest. On the other hand, a severe strain may require surgical repair and physiotherapy that can take months to regain full muscle function.
Why does it hurt when I lift my leg?
Pain when lifting your leg may be caused by a nerve injury secondary to nerve entrapment such as sciatica, where your nerves are compressed due to excess pressure surrounding it. Your leg may also hurt due to an injury or strain in the muscles used to lift your leg.
What muscle do you use when you lift your leg?
The muscles directly involved are the hip flexors (iliopsoas, sartorius, pectineus, tensor fascia lata, rectus femoris, adductor longus, and adductor brevis), the quadriceps muscles, and the hamstring muscles. The rectus abdominis and oblique muscles, located at the abdomen, indirectly contribute to lifting your leg by stabilizing your pelvis and hips.
What are the symptoms of a muscle strain in your leg?
Symptoms of a muscle strain include weakness of legs, prickling pain, and tenderness even at rest, bruising and swelling around the injured area, muscle spasms, cramping of muscles surrounding the injury, and an inability to use the muscle, causing you to be unable to lift leg while lying down.
How will I know if I have a nerve injury in my leg?
You will be able to identify a nerve injury by recognizing the symptoms which are, a pricking pain in your legs or feet, muscle weakness, numbness or a tingling sensation in your feet, feeling your leg is being compressed, frequent falls, or loss of balance and a buzzing sensation that feels like a mild electrical shock.
Can nerve injuries be treated?
Most nerve injuries can be repaired if caught early. These nerves are fixed by surgically exploring the damaged nerves and removing any injured tissues. Severed nerves can be reconnected if there is enough space to reattach them without making them too tight.
Unable to lift leg while lying down, though inconvenient, may not always be taken seriously. However, persistent symptoms should never be written off as something benign without getting it checked, as immediate interventions can do wonders in recovering damaged nerves.