The aim of the study was to evaluate the impact of inertial training on the muscle strength, on breast-cancer-related lymphedema, and on quality of life in breast cancer survivors. After a mastectomy, 24 women (age, 66.2 ± 10.6 years) were randomized to a training (n = 12) or control group (n = 12). The training group performed inertial training twice per week for 6 weeks with a training load of about 70% of the maximal force. Before and after training, we tested the maximum force of shoulder flexors, extensors, abductors, and adductors; body composition; breast-cancer-related lymphedema; and disabilities of the arm, shoulder, and hand. Inertial training significantly improved the strength in all tested muscles (from 32 to 68%; effect size (ES) from 0.89 to 1.85 in the impaired limb and from 31 to 64%; ES from 0.86 to 1.57 in the unimpaired limb). However, changes in the control group were not significant. Quality of life improved following treatment; the disabilities of the arm, shoulder, and hand score decreased significantly by 24.5% (ES from—0.29 to 1.38), p ≤ 0.05 in the training group and by 3.99% (ES from −0.49 to 1.14) in the control group p > 0.05. Breast-cancer-related lymphedema and body composition did not change significantly after the intervention in either group. We recommend inertial training for increasing muscle strength and improving quality of life in breast cancer survivors.

The aim of this study was to assess the relationship between the viscoelastic properties of tissues and breast-cancer-related lymphedema (BCRL). After a mastectomy, 46 females were allocated into a lymphedema group (L; n = 15, lymphedema occurred) and a control group (C; n = 31, lack of lymphedema). Bioimpedance spectroscopy was used to test BCRL. The mechanical properties of the tissues in both upper limbs were tested using myotonometry. In group L, tone, stiffness, relaxation time, and creep measured on the biceps brachii of the impaired limb significantly differed from the results on the unimpaired limb. In group C, the differences were not significant. Moreover, both tone and stiffness were inversely correlated with the level of lymphedema (r = −0.72 and r = −0.88, respectively), and both relaxation and creep were significantly related to the level of lymphedema (r = 0.71 and r = 0.59, respectively), when myotonometry was completed on the biceps brachii of the impaired limb in group L. The relationships were not significant in group C. Measurements of viscoelastic properties can provide useful information concerning lymphedema. Our findings suggest that significant correlations between selected mechanical properties of the tissues and BCRL can be used in BCRL detection and treatment.