Transporting patient to the ER. Moving patient from ambulance cot to ER bed. 3-ambulance personnel moving patient to ER bed. 2 people on cot side; one at head, one at side. 1 person on ER bed side; in middle. Grasped cot sheet with patient on it to slide over to ER bed. Person on cot side by head strained to pick up patient in order for patient to slide. Person in that position strained neck/upper back muscle which caused discomfort due to height of cot with patient on it. Patient was approximately 230 pounds.