SUPPLEMENTARY MATERIAL
Description of MRI–measurements and exercise program
This appendix has been provided by the authors to give readers additional information about
their study.
Supplement to: Koli J, Multanen J, Kujala UM, et al. Effect of Exercise on Patellar Cartilage
in Women with Mild Knee Osteoarthritis
.
TABLE OF CONTENTS
MRI PROTOCOL .......................................................Error! Bookmark not defined.
EXERCISE PROTOCOL ...........................................Error! Bookmark not defined.
1
MRI PROTOCOL
Prior to the measurements, experienced radiologists and technicians were trained specifically
for the MRI research protocol. On the previous day, or on the day of the MRI measurements,
the participants were asked to avoid any strenuous physical activity so as to minimize the
possible temporary effects of volumetric and compositional changes in the knee cartilage.
Also, to minimize the effect of diurnal variation on the follow-up measurements, all the
participants were imaged at the same time of day.
The participants were imaged lying supine. The participants lay in the scanner for about 40
minutes before the axial T2 imaging was performed. The flexion angle and rotation of the
knee was stabilized and the leg fixed in position with a leg holder. To prevent any
compression on the patella, a custom-made inflatable cushion was embedded inside the coil
to prevent. The imaging session included a standard clinical MRI series and T2 relaxation
time series. T2 mapping was performed using a sagittal multislice multiecho fast spin echo
sequence (field of view (FOV) 140 mm, acquisition matrix 256 x 256, repetition time (TR)
2090 ms, eight echo times (TE) between 13 and 104 ms, echo train length (ETL) 8, slice
thickness 3 mm). The slice with the thickest cartilage in the transversal plane located in the
middle third of the height of the patellar (sagittal plane) was selected for segmentation and
analysis.
For quality assurance purposes, a set of phantom samples containing certain concentrations of
agarose and nickel nitrate to modulate their T2 relaxation times were imaged following the
study protocol prior to the baseline and follow-up measurement sessions. No evidence of
scanner drift was observed during the intervention.
2
EXERCISE PROTOCOL
The training protocol was based on previous studies of exercises favourable to bone among
premenopausal, (14) postmenopausal, (36) and elderly women, (17). The expected training
frequency was three times a week for 12 months. All the exercise classes were supervised by
the exercise instructors, who were experienced in exercise guidance, and who had been
recently trained to supervise this specific exercise programme. The instructors also kept an
attendance record for each of the participants.
Each exercise class included a 15-minute warm-up, 25 minutes of multidirectional highimpact exercises (effective part) and 15 minutes of cooling down (non-impact exercises and
stretching). The effective component of the exercise classes comprised an aerobic jump
programme and a step-aerobic programme, which were administered at alternating intervals
of two weeks each. Both programmes included, in addition to jumps, accelerating and
decelerating through forwards and sideways movements with stops and turns to music.
During the first 3 weeks of the aerobic and step programmes, the trainees accustomed
themselves to jump training. During these periods, the exercises involved no foam fence
obstacles or step benches. Thereafter, the magnitude of the joint loading level was gradually
increased in the aerobic jumping exercises by raising the height of the foam fences from 5 to
20 cm (5 cm per 3-month period). In the step-aerobic programme, the magnitude of joint
loading was similarly increased by increasing the height of the step benches from 10 cm, the
lowest possible, to 20 cm. The bench height of 20 cm, starting from the beginning of the third
period, was retained during the fourth (last) period. The numbers of jumps performed in the
aerobic exercise periods were 208 in the orientation period, 168 in the first period, 180 in the
second period, 192 in the third period and 160 in the fourth period. The corresponding
numbers of jumps in the step-aerobic exercise periods were 216, 192, 180, 192 and 16
References
14. Heinonen A, Kannus P, Sievanen H, et al. Randomised controlled trial of effect of high-impact
exercise on selected risk factors for osteoporotic fractures. Lancet. 1996; 348(9038):1343-7.
17. Karinkanta S, Heinonen A, Sievanen H, et al. A multi-component exercise regimen to prevent
functional decline and bone fragility in home-dwelling elderly women: randomized, controlled trial.
Osteoporos Int. 2007; 18(4):453-62.
36. Uusi-Rasi K, Kannus P, Cheng S, et al.. Effect of alendronate and exercise on bone and physical
performance of postmenopausal women: a randomized controlled trial. Bone. 2003; 33(1):132-43.