Maintenance of Postural Steadiness throughout Chemotherapy Treatment

Abstract

Chemotherapy negatively affects postural steadiness of cancer patients, contributing to an increased risk of falling. Physical activity improves postural steadiness, and has been shown to reduce toxic effects of chemotherapy such as peripheral neuropathy and vestibular dysfunction; two known causes of decreased postural steadiness. PURPOSE: To determine whether postural steadiness improves in cancer patients undergoing chemotherapy following 12-weeks of exercise. METHODS: Cancer survivors (n = 25; mass = 79.0 ± 22.6 kg; ht = 1.66 ± 0.08 m; age = 61.3 ± 10.0 yrs) receiving chemotherapy participated in this study. Postural stability was assessed prior to and following a 12-week individualized exercise intervention that included cardiovascular, muscular strength, flexibility, and balance training. In both pre- and post- measures, center of pressure (COP) data were collected (1000 Hz) for 10 seconds in four conditions: rigid surface eyes open (RSEO), rigid surface eyes closed (RSEC), compliant surface eyes open (CSEO), and compliant surface eyes closed (CSEC) using the Bertec BalanceScreener™ (Bertec Corporation, Columbus Ohio). Root-mean square (RMS), mean velocity (VEL), 95% confidence ellipse area (95CE), and mean frequency (FREQ) were investigated (Prieto et al., 1996). A MANOVA with repeated measures (p < 0.05) was used to identify main effects between pre- and post-training assessments. RESULTS: From pre- to post- assessments mediolateral RMS decreased significantly for all conditions (p < 0.04 across all comparisons; RSEO by 35%, RSEC by 45%, CSEO by 43%, CSEC by 43%). A significant decrease was also observed in FREQ between pre- and post- assessments (p < 0.044 across all comparisons; RESEO by 29%, RSEC by 29%, CSEO by 31%, CSEC by 23%). No other variables changed significantly between pre and post assessments (p > 0.05). CONCLUSIONS: Postural stability in the mediolateral direction was improved in cancer patients after 12-weeks of individualized exercise training. In addition, there was evidence of increased postural control based on an increased mean frequency of the COP trajectory after training. These results suggest that exercise training is beneficial to postural stability in cancer patients undergoing chemotherapy treatment.