Fencing attitude of the dead bodies is caused by

PUGILISTIC ATTITUDE OR BOXING OR FENCING OR DEFENCE ATTITUDE: The posture of the body which has been exposed to great heat is often characteristic. POSITION: the legs are flexed at hips and knees the arms are flexed at the elbow and held in front of the body head slightly extended all fingers are hooked like claws contraction of paraspinal muscles often causes a marked OPISTHOTONOS in an attitude commonly adopted by boxers CAUSE: Coagulation of proteins occurs whether the person was alive or dead at the time of burning The flexor muscles being bulkier than extensors contract more due to which joints of all limbs are flexed. REFERENCE: The Synopsis of Forensic Medicine and Toxicology 29th edition page no: 161.