Ultrasound evaluation of diaphragmatic mobility and contractility after osteopathic manipulative techniques in healthy volunteers

Participants

• Numbers: 66 people (34 female and 32 male)
• Criteria of inclusion: asymptomatic healthy adults, absence of chronic pain or any acute symptoms during the 72 hours prior to the intervention, no pathology diagnosed
• Criteria of exclusion: pregnancy, breastfeeding, diagnosis of any pathology, chronic drug treatment, a medical history of abdominal surgery, OMT in the previous week
• Groups of study: three groups obtained by randomization
  • Group 1: OMT, 22 people (10 female and 12 male, mean age 41.9 years)
    • originally 23 people, 1 was excluded for inability to tolerate the osteopathic evaluation
  • Group 2: sham treatment, 22 people (11 female and 11 male, mean age 37.7 years)
  • Group 3: control, 22 people (13 female and 9 male, mean age 41.7 years)
    • more than half of the people were sedentary and about a quarter were smokers

Interventions and evaluations

• Evaluation of the diaphragm motion and thickness (related to contractility) using ultrasounds before and after the intervention:
  • both outcomes were evaluated through deep breathing
• Osteopathic evaluation of the right side of the diaphragm and of its connected structures before and after the intervention
  • in the pre-intervention assessment the aim was to evaluate possible somatic dysfunctions at the diaphragm level
  • in the post-intervention assessment the aim was to re-evaluate the somatic dysfunction with a score, in relation to the perceived change, from 1 (“severely worsened somatic dysfunction”) to 6 (“fully normalized somatic dysfunction”)
• Collection of data such as gender, age, BMI, smoking, practiced physical activity, type of work (sedentary or not)
• 1 30-minutes single session of OMT, sham treatment or control
• OMT: treatment of the diaphragm pillars and indirect techniques on the domes of the diaphragm, with instructions to the person to inhale deeply and then exhale all the air
• Sham treatment: fictitious treatment defined by a light touch on the thorax and sub-rib areas alternated with deep inspirations, without therapeutic intention
• Control: person lying on the bed and simply observed (wait)
• OMT administered by a practitioner osteopath under the supervision of an expert osteopath

Results

• Primary outcomes: Compared to the pre-treatment evaluation, the OMT induced a larger diaphragmatic excursion (on average, 68 mm to 82.5 mm) in a statistically significant way. This increase in the diaphragmatic motion was statistically significant also in relation to the two comparative interventions that saw the diaphragmatic motion remain stable, if not even slightly reduced.
  With regard to the thickness of the diaphragm, on the other hand, there were no differences neither between before and after treatments, nor comparing the different interventions.
• Further analysis: analyses related to the collected demographic data showed that, in the OMT group, the excursion of the diaphragm was adversely affected by having a sedentary occupation and, above all, by smoking (in this case, the diaphragmatic excursion increased only by 7mm, remaining far from statistically significant).
  Finally, the increase of the diaphragmatic excursion is correlated, in a strongly linear way, to the resolution of the somatic dysfunction (that is, the more the somatic dysfunction is normalized, the more the movement of the diaphragm increases).

Discussion

Compared to the sham treatment and to the control group, the OMT induced a relevant increase in the diaphragm motion.

The use of sham treatment could exclude that the effect of OMT was due only to a placebo effect and it could instead valorize the specific utility of the osteopathic techniques.

The analysis of the demographic data shows how being a smoker and having a sedentary profession could make people less receptive to OMT, therefore these subjects might need more treatment sessions to obtain a relevant result.
These results encourage future studies in which OMT could be performed on specific categories of people (e.g. athletes, singers) who need to control their breathing in a subtle way. Also, evaluating OMT effects on older people, whose diaphragm muscle tends to weaken, may show interesting results.

On a practical level, the correlation between diaphragmatic excursion and somatic dysfunction resolution emphasizes the importance of evaluating the state of the diaphragm through palpation.
The lack of effect on the diaphragm thickness, and therefore on its contractility, may be due to the fact that it is quite difficult for a session of OMT to actually influence this characteristic: long-term studies are therefore needed.
Furthermore, it would be a good idea to evaluate the entirety of the diaphragm (therefore also the left side) in future studies.