Progressive Muscle Relaxation

One meta-analysis and nine controlled clinical trials, including two pilot studies, were reviewed for this summary. There is, due to the low number of published studies and methodological weaknesses, only limited evidence for the effectiveness of PMR for cancer patients suffering from pain, anxiety, depression, sleep disorders and chemotherapy-induced nausea. It is, due to the impossibility of applying blinding, not possible to test the efficacy of PMS.

Meta-analysis

A meta-analysis examined the effectiveness of relaxation training among patients undergoing acute non-surgical cancer treatment including chemotherapy, radiotherapy, bone marrow transplant and hyperthermia6. In 14 of 15 studies reviewed, PMR, guided imagery and other modalities were lumped together and evaluated for their effects on symptom control. The review concluded that clinically significant reductions in nausea, pain, anxiety, depression, hostility and physical arousal (blood pressure and pulse) were achieved following relaxation training. However, because PMR was not analyzed separately, its effects on those outcomes were impossible to determine.

Controlled clinical trials

Three controlled clinical trials assessing the effects on sleep reported an improvement in sleep quality and insomnia but these trials have methodological limitations including small sample sizes, lack of non-treatment control group, lack of information on randomization procedure. It is not possible to draw clear conclusions about the benefits of PMR for this symptom. The first randomised trial examining the effects of a multi-modal psychological sleep management programme for people with a variety of different cancers (n=229),7 found that PMR (n=80) and autogenic training (n=71) were equally effective in enhancing various sleep parameters and reducing the need for sleep medication. The control group (n=78), which received only the standard rehabilitation programme, reported no changes in the use of sleep medication. Patients in all groups improved on all scales of the quality-of-life EORTC-QLQ-30 questionnaire, with the exception of pain which started at a low level and did not alter significantly. In the second trial, thirty patients diagnosed with different types of cancers and receiving different treatments were randomised to either PMR intervention or routine care for secondary insomnia8. The mean sleep onset latency was reduced from 124 to 29 minutes in the intervention group, but only from 116 to 104 minutes in the group receiving routine care. The third controlled clinical trial (n=27), among women with breast cancer undergoing adjuvant chemotherapy, investigated the effect of PMR training vs standard care on sleep quality and fatigue. The PMR group reported better sleep quality and less fatigue than the control group9.

Two randomized clinical trials investigating the effects on anxiety and depression reported improvements in both, anxiety and depression. Both trials have, however, methodological limitations and it is not possible to draw clear conclusions about the benefits of PMR for this symptom. The first trial including 147 patients with a variety of cancers who were treated in three different cancer centres, participants were randomised to receive either a PMR intervention or alprazolam for 10 weeks10. Both groups reported a decrease from baseline levels in anxiety and symptoms of depression, although patients receiving the drug showed a slightly more rapid decrease in anxiety and a greater reduction in depressive symptoms. The second randomized trial among patients with colorectal cancer who underwent stoma surgery (n=59), those who received training in PMR reported a decrease in state anxiety and an improvement in overall quality of life, but no improvement in disease-specific quality of life compared to a standard care control group11.

Although patients who participated in the three trials below reported an improvement in nausea and vomiting, all trials were small in numbers and have methodological limitations, so it is not possible to draw clear conclusions about the benefits of PMR for this symptom. In one study, 60 patients with different types of cancer were randomly assigned to PMR training or a control group where participants had their concerns and questions addressed for 10-15 minutes a day over a 72 hour post-chemotherapy period3. Patients in the PMR group experienced lower levels of nausea than the control group. In a further trial, 60 patients with different types of cancer were randomly assigned to PMR training, a control group where participants listened to music and a no intervention control group before their inpatient chemotherapy treatment12. The severity of vomiting was significantly lower in the intervention group. There were no significant differences between the groups for nausea. An uncontrolled pilot study (n=30) among hospitalised patients with haematological cancers undergoing chemotherapy reported that patients who had a single 25-minute PMR session had statistically significant reductions in nausea and vomiting levels immediately afterwards. They also reported an improvement in well-being (40%, 18 reports) and tranquility (20%, 9 reports)13.

There is insufficient evidence from one pilot study to be clear about the efficacy of PMR for cancer pain. The study examining variations in pain outcomes achieved after PMR and analgesic imagery interventions among 40 hospitalized patients with cancer pain4, found that both PMR and analgesic imagery produced greater improvements in pain intensity, pain-related distress, and perceived control over pain than the control condition. However, individual responder analysis revealed that only 41% of the participants achieved a clinically meaningful improvement in pain with the PMR intervention, and the pain levels swiftly (sometimes within an hour) returned to pre-intervention levels.