There are four commonly used sleeping positions that have proven to have negative effects on various parts of the body including the neck, hips, spine, and heart. These not recommended sleeping positions include: - The fetal position - This position has been connected to knee pain, lower back inflammation, deformities of the spine, and neck pain. - Stomach sleeping - Sleeping on your stomach for long periods of time has been shown to lead to irregular curvature of the spine, as well as neck inflammation and pain. - Half sitting, half laying - It is common to fall asleep while watching a movie or reading on the couch, or sitting in bed on your phone, but falling asleep in this position regularly and for extended periods of time has been shown to place increased strain on the spine, resulting in swelling and pain in the shoulders, and lower back pain. - Sleeping with your head resting on your arm - While this sleeping position is less common, if you happen to fall asleep in this position and stay in the position for an extended period of time, it can lead to nerve damage in the arm. This position is commonly held by those who fall asleep at a table or rest their head on the arm of a chair with their arm acting as a pillow. Some of these positions may be more comfortable for you, helping you fall asleep faster, but, if possible, it is highly recommended that you try to sleep on your back, without allowing your head to fall side to side while sleeping, as this is the most effective position in reducing the strain placed on any one part of the body. You can sleep on your side as well if that is more comfortable, but it is important to try to maintain a straight line from the head down to the spine so that the neck, lower back, and hips are all aligned.