Article written by:
B.Physio (Hons), M.Physio (Musculoskeletal)
There are some common misconceptions surrounding the practice of neck manipulation, also known as adjustments, or cracking or cavitation.
It is a technique regularly performed by a variety of health practitioners, including physiotherapists, and involves a gentle, small amplitude movement of the neck, but at sufficient velocity to overcome the muscles’ protective response. The movement is associated with an audible “pop”, and is just one method of improving movement and pain in the neck (or sometimes head, shoulder or arm).
“The popping noise is a release of nitrogen.”
Every joint has a small amount of synovial fluid within it, to nourishing the cartilage and help cushion and distribute forces. Spinal joint manipulation causes ‘cavitation’; when the joint surfaces are quickly separated the pressure within the joint drops, causing the carbon dioxide dissolved in the synovial fluid to form a bubble, and then rapidly collapse back, causing the popping noise. It takes approximately twenty to thirty minutes for this gas to fully dissolve back before it will cavitate again.
“The technique is perfectly safe.”
The Vertebral Artery runs through small holes in the sides of the cervical vertebra up into the skull to supply the back part of the brain. Manipulation of the neck has been linked to damage of this artery, and although exceedingly rare, it can lead to serious complications such as stroke or even death. The risk of death or serious vascular accident varies from as much as 1 in 400,000 to as little as 1 in 4,000,000. Physiotherapists are trained to conduct a risk screening assessment (in depth questioning plus physical testing) and discuss treatment alternatives so that you may make a fully informed decision about whether to undergo cervical manipulation. In the right hands, manipulation is very safe, and there have been no documented complications from physiotherapy manipulation.
“It’s better if I don’t know it’s coming. I can relax better that way.”
As mentioned, you should be fully informed and give your verbal consent prior to any cervical manipulative procedure. There are other ways of relaxing the muscles such as heat and massage, without needing a “surprise attack”.
“Cracking the neck puts the vertebra back in place.”
Radiographic imaging studies do not demonstrate measurable change in the position of spinal joints after manipulation. Whilst the cavitation will temporarily improve the freedom of movement of the joints, it is debatable whether subtle joint subluxations are reduced and more normal spinal alignment achieved.
“If I crack the neck too much, I’ll get arthritis.”
There is no proven link between repeated spinal manipulation and osteoarthritis. Unfortunately the main evidence comes from studies of habitual “knuckle crackers”, which show no increased incidence of joint degenerative changes, but do show some loss of grip strength. It is possible that excessive manipulation may similarly weaken the neck.
“My therapist is the only one who can fix my neck when it’s out.”
It is true that many people gain quick relief from manipulation, but your therapist should also be able to show you remedial exercises and teach correct posturing in order to fix the underlying cause of the problem. This way you can maintain your own neck and spinal health. There is good evidence that core stabilisation exercises help resolve back and neck pain, and headaches, and prevent future recurrences. Ask your physio how!
There should be no second thoughts on preparing before and after any sport or fitness training. This may help athletes to prevent injuries and pull through to get ready for their next challenge.
There is much research available on warm up, static versus dynamic stretches and its necessity, to perform better during any event. From budding to professional athletes, everyone concentrates on their groundwork before their practice or events which are supported by their parents and coaches/trainers, but not many do their warm down properly unless they are guided by trained professionals.
In my experience, most of the athletes I have assessed and treated were lacking in cooling down after practice or competition. There wasn’t enough importance placed on preparing for the next game or training.
Cooling down is as essential as warming up. Muscle inflexibility is directly connected to altered biomechanics which may lead to potential injury even with regular preparation before training or game. To continue to lessen the stresses on your precious body, cool-down also plays a significant role.
In this increasingly fast-paced and technologically-driven world, the importance of proper warm up and cool down processes does tend to get overlooked due to lack of time. However it is simply a matter of being innovative before we work out or compete. This can be done by either brisk of fast walking, or even jogging to the game (or gym), and utilisation of dynamic drills and proper stretching prior to working out which can minimise the risk of injuries.
If you do not have the time for a static stretch, make sure you stretch before hitting the bed by spending at least 10-15 minutes to focus on the above-mentioned muscles.
Be good to yourself and your body, so that you can allow it to adjust and prepare properly for the next challenge!
There are many different methods of warming up and cooling down, but here is just one example:
- 5-10 minutes of jog to increase core body temperature
- 5-10 minutes of dynamic stretches – raise muscle temperature, elongates the muscles, stimulates the nervous system which may reduce the chance of injuries like strain etc.
- 10-15 minutes of game related drills (in footy for example this would involve lower leg activities, and technique practice such as ball kick, tackles, quick ball passes etc.)
- 30-40 metre quick sprints with ball passes (paying attention to running technique with good upright posture, hip & knee lift with good arm swings)
- 5-10 minutes of walking to lower your pulse to average level and to reduce the body temperature
- 10-15 mins of static stretch which may help in maintaining flexibility
- Be careful not to stretch beyond the available range of movement of a particular joint, which may cause micro or macro damage to a muscle or a group of muscles
- For Footy players – stretch your calves, hamstrings, quads, adductors (inner thigh), gluts, lower back, front chest, shoulders, and elbow/wrist/fingers. Don’t forget your neck too.
- Be kind to your precious body!