Cottingham, JT, & Porges, SW. (1988). Effects of soft tissue mobilization (rolfing pelvic lift) on parasympathetic tone in two age groups. Physical Therapy, 68(3), 352-6.
This study examined the pelvic lift mobilization procedure and alteration in vagal tone measured via heart rate variability. The pelvic lift is a soft tissue manipulation thechnique from the Rolfing method of manual therapy or structural integration. It involves a combination of posterior tilting and pelvic traction with simultaneous pressure to the epigastrium . The paper does a fine job clearly defining the pelvic lift technique, value in heart rate variability measures, and claims to be one of the first to examine HRV responses to manual therapy treatment.
Thirty total subjects were divided into age-based groups (26 to 40 year old and 55 to 68 years old) and experienced the same treatment procedure with continual monitoring of heart rate variability via electrocardiogram during alternating 3 minute baseline and manipulation periods. Sujects received both the pelvic lift technique and also simple durational pressures each with HRV assessment before and after, in random order. Results indicated that the only the younger group (mean age 32) demonstrated increases in heart rate variability with only the pelvic lift and not with durational touch. It also demonstrated that heart rate variability was a better method for determining ANS state than simple heart rate measures.
This information is valuable as it establishes the value in heart rate variability assessment in manual therapy settings over those of simple heart rate measures. Additionally, this is valuable information as there may be an age-dependent and definite treatment dependent results on HRV indicating that certain techniques are more effective than others that can help the therapist maximize benefits.
Why the age gap exists in heart rate variability changes is a question that must be answered with further research.