Arm circumference measurement for women with breast cancer–related lymphedema (BCRL) using a tape measure is reliable, valid, and widespread in clinical practice. Arm position
for measurement varies among therapists and lacks uniformity in the literature.
To examine the effect of arm position
on total arm and segment volume for both arms in healthy women and women with BCRL.
Fourteen women in the maintenance phase of treatment of unilateral BCRL and 16 healthy women matched for age and body mass index. Three sequential circumferential
measurements were performed in 2 different resting arm positions (90° supported forward flexion, dependent alongside the body) in both arms during 1 session. Arm volume was calculated using the summed truncated cone formula.
A nonsignificant interaction effect of arm (small vs large), position (horizontal vs vertical), and group (women with BCRL vs healthy women) on limb volume was noted (F1,28
= 3.30, P
= .08). While among women with BCRL (study group), the mean percentage volume change in the large arm between positions was lower than in the small arm (1.37% ± 1.97%) vs 1.61% ± 1.99%, respectively), the opposite was noted among healthy women (control group) (3.36% ± 1.45% vs 2.46% ± 1.59%, respectively).
Participants with BCRL presented with nonpitting mild lymphedema, and 2 specific positions that were selected limit the external validity to this stage of lymphedema and to these positions.
Measurements should be performed in the same position; if not, according to the findings of this study, testing for systematic bias between positions should be performed.