Efficacy of high-velocity low-amplitude manipulative technique in subjects with low-back pain during menstrual cramping

Participants

• Number: 12 women
• Criteria of inclusion: age from 22 to 36 years, patients, students or staff (or their friend or spouses) of theDepartment of Osteopathic Manipulative Medicine at the University of Osteopathic Medicine and Health Sciences College of Osteopathic Medicine, Des Moines, Iowa; a history of menstrual cramping with unilateral or bilateral low back pain localized in the lumbar spine erector muscles between L2 and S1; no history of a different type of low back pain and no previous accidents or traumas to the lumbar spine
• Groups of study: 2 groups
  • Group 1: OMT, 10 women
  • Gruppo 2: no treatment, 10 women
  • 8 women were considered in each group, at a month distance from each other (first group 1 and then group 2)

Interventions and evaluations

• Sensory, motor and neurological physical evaluation at the beginning of the study
• Palpatory evaluation at the beginning of the study
  • muscular hypertonicity lateralized towards the side producing more pain, with concomitant prominence of the transverse processes of the vertebrae from T10 to L2 towards the same side, inability to recreate the pain in the absence of menstrual cramping
• Evaluation of the muscle activity of the lumbar area through EMG before and after the intervention (in both cases, the examination was repeated twice)
  • the examination was carried out by asking women, after 5 minutes of rest while lying prone, first to extend the lumbar area and then to flex it, maintaining the position for 5 seconds in both cases
  • from the analyses carried out, only the EMG evaluation was used in case of extension, as the movement was easier to control and produced more consistent results for the analysis
• Valutazione prima e dopo l’intervento e a metà ciclo (quando il dolore non era presente) di creatinchinasi totale, lattato deidrogenasi (totale e isoenzimi) e mioglobina tramite venipuntura
• 1 OMT session of about 10 minutes during those menstrual cycle days in which dysmenorrhea with low back pain would manifest
• OMT: structural evaluation of any compensatory mechanisms, muscle energy techniques on hip, pelvic and pubic muscles, sacral mobilization and high-velocity low-amplitude techniques on lumbosacral and thoracolumbar articulations, thoracic inlet and cervical spine
• No treatment: rest, lying for the same amount of time as for the OMT duration
• OMT performed by two students, specifically trained before the study to follow a standardized protocol
• The women were instructed not to take any non steroidal analgesics before the physical evaluation
  • although 2 women had assumed ibuprofen because of the high pain intensity, they remained in the study anyway as: the low back pain persisted; the EMG showed a result comparable to a low back pain situation

Results

• Primary outcomes: after the intervention, OMT favored a decrease of muscular activity detected through EMG by 25%, obtaining a statistically significant result, a fact that did not occur in the group with no treatment. While 9 women out of 10 showed a decrease in EMG mean signal in the OMT group, only 5 out of 10 showed a similar decrease with rest. In addition, all women treated with OMT did no longer manifest spontaneous muscle activity during menstrual cramping, a spontaneous activity which is often correlated specifically with low back pain. On the contrary, this spontaneous muscle activity remained present after rest alone.
• Secondary outcomes: no differences were detected in the hematologic examinations before and after both OMT and rest alone. However, the myoglobin/creatinine ratio was higher during the days when menstrual cramping was present than during the days of the cycle when they were statistically significantly absent.

Discussion

OMT proved to be able to positively affect the muscular activity in case of menstrual cramping, consequently reducing low back pain, as reported by all participants, who immediately after OMT reported an immediate relief.
Of great interest is the result showing that OMT seemed to have acted positively even on those two women who had not found any relief with ibuprofen.

The lack of changes in hematologic tests may have several explanations: first of all the fact that, after 5-12 hours from the OMT, the menstrual cramps returned, although less intense than at the beginning.
Therefore, more in-depth studies are needed to well understand the efficacy of OMT and the best method to treat women with dysmenorrhea, especially associated with low back pain, which could depend on autonomic and somatic nervous pathways stimulation, mediated by the inflammatory processes underlying dysmenorrhea.