Why does hip fracture cause inability to bear weight?

When the upper thigh bone breaks near the hip, forces from the foot can no longer pass smoothly through the bone into the pelvis. Putting weight through the leg may cause movement at the fracture, sharp pain and protective muscle spasm. The nervous system responds by limiting effort, so the leg may buckle or feel unusable. Some people can still move the foot or bend the knee even when the hip is fractured; that does not make weight bearing safe. A fracture can follow a fall or direct force, while reduced bone strength can allow a break with less force. Other injuries and conditions can also prevent standing, so an examination and imaging are essential.

Do not stand, walk or ask someone to pull you upright. Keep the painful leg supported in the position that causes least discomfort, and call emergency services after a fall or sudden severe pain. Keep the person warm and still while waiting. Avoid giving food or drink if urgent surgery may be needed, unless emergency professionals advise otherwise. Do not apply strong pressure or attempt to realign the hip. If the person is already using a walking aid, do not change the weight-bearing plan without clinical instruction.

Inability to bear weight after an injury needs urgent assessment, even if the skin looks normal. Seek emergency care for severe pain, a shortened or outwardly turned leg, numbness, a cold or pale foot, faintness, confusion or heavy bleeding. Prompt help is also needed when sudden hip pain prevents standing without a clear fall, particularly in someone with fragile bones. Safe transport matters: moving the person unnecessarily can worsen pain and injury.

Ask: Is the fracture stable? May I place any weight on this leg? Which aid should I use, and who will teach me? What pain relief is suitable? Do I need surgery or another treatment? How will blood clot, pressure injury and falls be prevented while I am less mobile? When should rehabilitation start?