The relationship between applied pure moments at the occiput and the resulting rotation at the atlanto-occipital and atlantoaxial joints were qualified. In axial twist, with a moment of 0.3Nm, a mean rotation of about 2.5 deg. and 23.3 deg was observed resp.. Both the atlas and axis contribute to produce lateral bending motion. The ratio between extension and flexion rotations at 0-c1 was 2.5 : 1 . Lateral bending and axial rotations were strongly coupled to each other. The occipito-atlanto-axial complex exhibited a large 'neutral zone' compared to lower cervical segments.
-1) relative small loads are needed to produce large rotations across the 0-c1-c2 complex. This is supportive of the notion that ligaments across occipito-atlanto-axial complex are lax and the head is, therefore, held firmly to the neck principally by muscular actions.
-2) 85-90% of the axial rotation occurs across the c1-c2 unit of the complex.
-3) in lateral bending, the 0-c1 and c1-c2 units contribute almost equally to the primary lateral bending rotation.
-4) further research is needed to examine the moment-relationships, using juvenile specimens, to the extreme range of motion.
Final case was a bus driver whose bus fell off a road during a landslide. He saved several children and ran some 15km back to a farm to get help. When the local emergency services were slow in coming, he ran back to the bus, where his wife was looking after the surviving children. At the end of the day, the police finally arrived to find the carnage. Eventually, everyone was evacuated to a local hospital and later some were flown out to larger hospitals. When the adrenalin finally wore off, he started to feel pretty bad. When he stated this to the medical officers, they took some X-rays and made him a cup of tea and stated he would be O.K. He then rang an Intensivist medical friend of his, who drove 180km to pick him up and drove the equivalent back again, where his hospital detected 5 vertebral fractures, including a dens fracture (1992).
Spondylolisthesis Causes, Symptoms, Treatments - WebMD
In one case, a truck driver had his several tonne load fall on him. He drove his truck to the hospital where he was given a mild painkiller and told to take it easy. He drove from Port Augusta back to Lithgow (approx 2000km) and then took 6 weeks off work feeling pretty miserable. Fortunately, a friend visited him who happened to be a doctor, who drove him to the local hospital where he insisted on correct imaging which resulted in an air-ambulance evacuation and emergency surgery (1998).