MRI study of dynamic isolated lumbar extensor resistance training effect on multifidus muscle cross sectional area and fat infiltrations in patients with non-specific low back pain - a pilot study.

Non-specific low back pain is very common; 60 to 80 percent of the Western
population will experience an episode during their lifetime. The lumbal
multifidus muscle plays a role in non-specific low back pain. 80% of the people
with non-specific low back pain have lumbal multifidus muscle atrophy. Recently
research has shown low back pain is treated effectively with reactivation and
strengthening of the small muscles of the back. After this therapy long term
stabilization of the vertebral column is improved. OriGene developed an
isolated low back training with positive clinical results in patients with
non-specific low back pain. To understand the effects of this therapy, it is
relevant to study the effect of this therapy on the lumbal multifidus muscle.

The objective of this prospective study is to answer the question: "Leads
isolated dynamic resistance training of the lumbal extensor muscles to
decreased multifidus atrophy and will MRI show an increasing multifidus cross
sectional area and decrease of multifidus fat infiltration?"
Secundary question: "Is there a relation between decreasing multifidus atrophy
and self experienced functional low back pain?"
This is a pilotstudy, if this study shows results it will be expanded to a
study with a larger population.

At the start of the study patients will undergo an MRI scan, in which the cross
sectional area and fatinfiltration percentages of the lumbal multifidus muscle
will be measured in the axial plane at three disci levels: L3-L4, L4-L5 and
L5-S1. Patients will also fill in validated questionnaire concerning functional
(ADL-) limitations caused by low back pain. After this 20 minutes MRI scan the
patients will undergo once a week an isolated dynamic resistance training
during ten weeks, in which the lumbal extensor muscles will be trained. They
will not undergo any other therapy. After the ten weeks of training, the
interval of training will depent on the patients' need.

Thirteen respectively twentysix weeks after the baseline MRI a second
respectively thirt MRI scan will be made, in which the cross sectional area and
fatinfiltration of the lumbal multifidus muscle will be measured at the same
locations. Again patients will fill in validated questionnaire about low back
pain.

This study will demonstrate the effect of isolated dynamic resistance therapy
on cross sectional area and fatinfiltration of the lumbal multifidus muscle.
This effect will be compared with the answers of the questionaire.

This study is a pilot-study. As control-group five of the twinty patients will
undergo an extra MRI, four weeks prior to the baseline MRI. During these four
weeks patients will undergo no therapy.

The participants will undergo once a week an isolated dynamic resistance
training during ten weeks, in which the lumbal multifidus muscle will be
trained. They will undergo no other back muscle therapy and no medicine
restrictions are imposed. After ten weeks the interval of training will depend
on the participant's needs. Except for the MRI scans their treatment equals the
regular treatment.

Participants will undergo dynamic isolated lumbal extensor resistance training
and three or four MRI scans. The trainig will take place under direct
supervision of a physiotherapist. The MRI scans have no radiation exposure and
no contrast will be administered. Before a participants will be included in the
study, he/she will be asked whether he/she has metal in his/her body (e.g.
pacemaker of metal splinter in the eye) or is claustrophobic.