Cardiovascular responses to repetitive McKenzie lumbar spine exercises

Background and Purpose. Repetitive exercises of the type recommended by McK enzie for the lumbar spine, such as flexion and extension exercises in stan ding (FIS and EIS) and lying positions (FIL and EIL), have been used in the management of low back pain for over 20 years. The cardiovascular effects of exercises that involve postural stabilization and the arms and of exerci ses performed in a lying position are well known. Therefore, the purpose of this study was to examine the cardiovascular effects of 4 exercises used i n the McKenzie system. Subjects and Methods. One hundred subjects without c ardiovascular or cardiopulmonary disease (mean age = 31 years, SD = 6.1, ra nge = 22-44) and who were representative of people susceptible to low back pain were studied. Subjects were randomly assigned to I of 4 exercise group s (ie, FIS, EIS, FIL, and EIL). Subjects performed sets of 10, 15, and 20 r epetitions of the assigned exercise, with a 15-minute rest between sets. He art rate, blood pressure, and rate-pressure product (an index of myocardial work) were recorded before and after each set of repetitions. Results. Aft er 10 repetitions, flexion and extension in lying were more hemodynamically demanding than in standing. This trend persisted for 15 and 20 repetitions ; however, at 20 repetitions, the hemodynamic demands were different across exercise groups (ic, FIL > EIL > FIS > EIS). Discussion and Conclusion. Re petitive exercises of the type suggested by McKenzie for the lumbar spine c an have cardiovascular effects in people with no cardiovascular or cardiopu lmonary conditions. These effects may be important with respect to cardiac work, and patients for whom these exercises are indicated should have a car diac and pulmonary risk factor assessment to determine whether heart rate a nd blood pressure should be monitored.