Reducing pain and disability for patients with chronic neck pain : results of a double-blind randomised controlled trial comparing strength to endurance training
Neck pain is a common musculo-skeletal problem in the industrialised world with fifty
to ninety percent of people experiencing one or more episodes of neck pain during their
lifetime. The majority recover quickly from these episodes, but five percent of all
cases persist for more than three months. The recurrence rate is high at sixty-percent. The cost to the individual in terms of reduced earning capacity and personal and
family distress is very high. The cost to society in terms of lost productivity and
compensation payouts is reported to be substantial. Thus, there are very compelling·
reasons for finding the most effective therapies for neck pain.
Most whiplash injuries to the neck recover spontaneously within three months, but
chronic symptoms develop in some 25% of individuals, where pain persists more than
three months after the initial injury. If associated restricted mobility persists for
more than a few weeks, joint immobility becomes progressively more complete. Disuse
atrophy, with attendant lowered fatigue resistance, also occurs. The link between
muscular weakness and chronic low-back pain is well established. Research also
suggests a correlation between weak cervical musculature and chronic neck pain.
Further, as neck muscle strength is shown to be a controlling factor in the stability of the
cervical spine it seems logical to seek safe and effective ways of strengthening it.
However, many clinicians feel that strength-training the cervical spine, where the
emphasis is on exercising slowly with heavy weights, is unsafe and may even aggravate
patients' symptoms . Other clinicians maintain that muscular endurance-training,
where the emphasis is on exercising fast with light weights, may be more suitable in the
initial stages of training, the theory being that it facilitates maximal blood perfusion
thereby maximising healing. Hence, muscular endurance-training is prescribed
more often because clinicians believe it is less likely to harm patients, but will still
increase their muscular strength. It is also important to establish whether ·physiological changes in muscle size and
structure resulting from different training methods impact differently on people's pain
and disability. Therefore, the research questions of this thesis are, for patients with
chronic neck pain, when compared with muscular endurance-training, (1) does strength training
result in a greater increase in muscle strength? (2) Does strength-training result
in a greater reduction in pain and disability? The underlying rationale of strength
training the cervical muscles, therefore, is that by strengthening the weakened muscles
of the neck the symptoms of pain and disability that accompany chronic neck pain will
be significantly reduced