why do my legs bend when i sleep?
Sleep Positions

Why Do I Sleep with One Leg Bent Up?

Last Updated on: 16th September 2023, 07:29 pm

We all have a preferred sleeping position, which seldom involves lying pencil-straight. Whether you consciously or unwittingly move in your sleep, you may curl and bend one leg at night.

Bending the leg can assist with body temperature regulation.

You can retain warmth or allow a foot to hang from the bed to cool off. This sleep position also aids weight distribution in a shared bed and enables a tall person to stay under the covers.

If you adopt this position without realizing it, you may have Periodic Limb Movement Disorder (PLMD), which involves cramping, jerking, and twitching the legs.

Unfortunately, there can be unintended consequences to sleeping with one leg bent.

You may take up more bed space than intended, disturbing a partner’s sleep. Also, the position can exert pressure on the pelvis and lower back. Restricted blood flow can lead to numb feet upon waking.

Place a pillow between the knees when you go to bed. This can prevent you from subconsciously bending one leg while you sleep and could assist with spinal alignment.

Why Do My Legs Bend When I Sleep?

Some of us consciously sleep with one leg curled up, especially taller people.

A standard double bed is 6 feet and 3 inches long, although some of the space may be lost to a headboard, and the mattress could be 1-2 inches shorter.

Someone over 6 feet may find their feet hanging from the bottom of the bed if they were to lie straight. Curling the leg before sleeping can keep your body under the blankets.

Interestingly, there are benefits to sleeping without blankets that are worth exploring.

You may prefer to bend your legs to retain a sleeping position throughout the night. If you’re prone to tossing and turning, bending the leg while on your stomach may hold you in place.

For many people, bending the leg is an involuntary action that arises during sleep. However, there are other plausible explanations regarding why it happens:

is it bad to sleep with one leg bent?

Weight Distribution

You may feel compelled to lift and bend your legs at night to manage weight distribution in a bed.

This is especially likely if you share your bed with a heavier partner because their weight may create a divot in the mattress that forces you to move to one side.

It can reduce the pressure of your weight in the bed, especially in the supine position. This can be comfier if you have a back issue, but bending one leg can exacerbate the problem in the long term.

Some people adopt the fetal position when sleeping to minimize pressure on a body part.

You’ll bend both legs in this position, which is preferable to just one limb. This position can exert pressure on the spine and neck, so consider adjusting how you sleep periodically.

Temperature Regulation

Maintaining an appropriate body temperature is a vital component of restful sleep.

Frontiers in Neuroscience explains how our core body temperature drops as we drift further into sleep, particularly when entering the REM sleep phase.

While reducing body temperature can help you sleep, feeling cold can keep you awake. Bending one or both legs can help the body curl up and retain warmth from blankets.

If you feel too hot and sleep at the edge of a bed, you can bend the knee to hang one leg out of the side of the covers. Body heat is lost through the extremities at night, including the feet.

Periodic Limb Movement Disorder (PLMD)

There could be a medical explanation for a tendency to bend your leg at night.

The first is Restless Leg Syndrome (RLS), which compels somebody to regularly fidget with the legs.

If you only bend the legs during the subconscious of sleep, the concern is likely to be Periodic Limb Movement Disorder (PLMD). Sleep Medicine Reviews stated that up to 11% of people have PLMD.

Anybody with RLS is likelier to have PLMD, which manifests while we sleep. This condition is most common among the left-handed and people aged 60+.

Other common causes of PLMD include:

  • Iron deficiencies.
  • Diabetes or pre-diabetes and associated nerve damage to the legs and feet.
  • Side effects of medications, like antidepressants.

PLMD can be controlled with medication, supplements, and lifestyle changes.

Is it Bad to Sleep with One Leg Bent?

Sleeping with one leg bent up isn’t ideal if you share a bed because it causes you to take up more space and potentially knee a partner in the back, disturbing their rest.

Even if you sleep alone, you may experience discomfort when you wake up after adopting this position overnight. What are the adverse effects of sleeping with bent legs?

Pressure On The Pelvis

Some people bend their legs and knees to relieve pressure on the lower back while sleeping.

If you only bend one leg, this will lead to uneven weight distribution, and more pressure will be exerted on one side of the pelvis than on the other.

Initially, this can lead to soreness and hip pain when you awaken. This may pass, but the wear and tear will accumulate after weeks, months, and years of sleeping this way.

Eventually, this lack of balance can cause misalignment of the spine. The posture will suffer, and back problems will become more pronounced.

If you decide to bend a leg while you sleep, it’s advisable to elevate both limbs.

Why can't I sleep with my legs straight?

Numbness in The Feet

Bending one knee will restrict the blood flow to the lower leg while you sleep.

If you adopt this position occasionally, it isn’t a significant concern. Over time, it can lead to peripheral arterial disease or varicose veins.

Limited blood flow can also cause numbness in the feet (pins and needles) when you wake. The feeling won’t take long to return to the foot, but avoid walking until the numbness subsides.

You’ll feel unbalanced if you have one numb foot and one foot with feeling. Couple this with the grogginess associated with waking from a deep sleep, and you risk slipping and falling.

How To Stop Bending Your Leg in Your Sleep

You may eventually experience consequences if you regularly sleep with one leg bent. Thankfully, there are techniques you can adopt to train yourself to adopt a different sleeping posture.

The simplest approach is to sleep with a pillow between your legs.

This can be done in any sleeping position, whether you prefer to lie supine, prone, or on your side. Sleeping on your left side with knees separated by a pillow will aid digestion and sleep.

Exercise your legs during the day, and minimize caffeine and alcohol before sleep. These lifestyle solutions for RLS will help you maintain a single sleep position overnight with less fidgeting.

Sleeping with one leg bent may initially feel comfortable, but it’s not always a sustainable position for restful sleep and good posture. If it’s a problem, you can adjust your sleeping position.