Novel methods to increase core muscle activity in older adults

[Purpose] This study aimed to test whether a combination of specific postures and movements can increase trunk muscle activity in older adults. [Participants and Methods] Forty-six community-dwelling older adults (mean age: 83.9 ± 4.5 years) were living independently without the need for nursing care. The thicknesses of the external oblique, internal oblique, and transversus abdominis muscles were measured during the following three tasks: task I, natural sitting posture; task II, specific sitting posture to promote activity of the deep trunk muscles; and task III, task II plus a pushing down motion using both upper limbs. During each task, an ultrasound imaging device was used to measure the thicknesses of the external oblique, internal oblique, and transversus abdominis muscles on both the left and right sides according to the time required for expiration. [Results] Significant differences were found in the thicknesses of the internal oblique and transversus abdominis muscles between tasks II and III. Among the three muscles, the transversus abdominis showed the highest increase in thickness. [Conclusion] High activity of the trunk muscles, especially the transverse abdominis, can be achieved via specific sitting positions/tasks and further manipulations to increase the intra-abdominal pressure in both upper limbs.