Low frequency therapy is a form of vibrational sound therapy. It provides gentle vibrations for healing purposes while producing a gentle hum and vibrotactile sensation in the body.
LFV is often utilized in tandem with music; however, less is understood regarding its standalone effects. [1]
Patients were evaluated at various frequencies until one provided effective pain relief of at least 50%, including NRS scores, pulse width data and amplitude measurements.
1. Pain Relief
At present, only case series data exist from low frequency therapy with respect to significant pain relief for selected patients; thus the SENZA-PDN RCT seeks to evaluate whether 10-kHz SCS combined with conventional medical management (CMM) offers greater or equivalent neuropathic limb pain relief versus CMM alone in patients suffering from spinal cord injury (SCI).
Contrary to traditional transcutaneous electrical nerve stimulation (TENS), which uses square waveforms to produce paresthesia, 10kHz HF-SCS does not rely on this effect for its effectiveness. Although its exact mechanism of action remains unknown, its results could involve either descending modulation or neurogenic mechanisms of pain relief.
Prior studies of subperception SCS have successfully demonstrated blinded analgesia using higher frequencies (2-10 Hz) or trains of pulses below threshold for paresthesia, yet these modalities had several drawbacks that hinder clinical implementation, such as long charging times for devices and the need to conduct blind anatomical searches in search of optimal placement.
At a pilot study, patients suffering from chronic myalgia in their neck, shoulder, and back were randomly assigned either personal low frequency stimulation (PLSG) or physical therapy (PTG). Pain intensity was assessed using surface electromyography and McGill pain questionnaire before and after receiving either treatment option for three weeks. When compared to PTG, PLSG reduced surface electromyography (sEMG) across all three regions as well as reduced VAS pain levels on shoulders and back respectively compared with PTG; patients reported moderate to substantial improvement; patients also preferred this program over other available options available options; results suggest there may be wide variation of effective subperception SCS parameter combinations available, but optimizing this sweet spot is key.
2. Relaxation
Low frequency sound therapy is a form of vibrational healing designed to induce relaxation and healing. Sessions involve clients lying on a lounge with transducers that emit low-frequency sound waves and vibrations in sync with soothing music for an immersive experience. These soothing vibrations stimulate neurotransmitter release, nerve cell activation and promote relaxation responses within the brain for enhanced health benefits such as reduced pain and stress management as well as decreased muscle tension and better sleeping patterns.
Vibroacoustic therapy has an established scientific basis. By employing frequency, vibration, and soothing music to activate the body’s natural healing response and help manage pain, improve sleep quality and mood, promote overall wellness and overall well-being. Montare Outpatient offers comprehensive physiotherapy services including vibroacoustic therapy to ensure our clients achieve health in whatever capacity they desire.
Researchers discovered that LFS combined with music listening had an impactful combination on university student’s parasympathetic nervous systems. This trial result indicated LFS may help manage elevated stress responses; more research needs to be conducted using various research experiment designs as well as objective measures of physiological function and subjective perceptions to fully explore its benefits.
Another study explored the relationship between frequency and neural dosing by measuring current amplitude, pulse width and charge-per-second (frequency x pulse width), to ascertain an effective dose of vibrational stimulation. Results revealed that both current amplitude and pulse width increased with increased frequency while effective neural dose decreased due to habituation and saturation of the thalamus; suggesting it might be possible to break this cycle by changing LFS frequency over time to optimize treatment effectiveness.
3. Stress Reduction
Vibroacoustic therapy uses sound waves and vibration combined with soothing music to facilitate relaxation, relieve stress, and foster healing. The vibration frequencies used are tailored specifically for human bodies to activate neurotransmitters release and nerve cell activation – creating an almost dream-like state of meditation and deep relaxation.
Vibroacoustic therapy stands out as an invaluable, noninvasive and drug-free modality, making it an indispensable addition to traditional medical treatments. Vibroacoustic therapy’s versatility in managing pain management, stress reduction and sleep enhancement further reinforces its place within healthcare systems worldwide.
Research was conducted with university students who experienced elevated stress due to multiple environmental stressors during a pandemic, and results indicated that listening to HF-amplified music increased PNS activity more than listening to LF-amplified music, measured as stress recovery ratio.
Subjective perception was measured using the Visual Analogue Scale for Stress (VAS-S), an easy, well-established and widely available measurement tool with excellent psychometric properties. Furthermore, physiological measurements were taken before and after each session of vibroacoustic therapy.
This study is an important milestone towards demonstrating the efficacy of vibroacoustic therapy as an effective, noninvasive, and clinically relevant way to improve human wellbeing. Vibroacoustic therapy’s potential to activate parasympathetic nervous system activity and influence subjective perception could make it a useful stress relief tool – especially helpful for individuals living with both eating disorders and co-occurring PTSD who experience increased stress responses that contribute to maladaptive coping behaviors that exacerbate both disorders. These results could open a new path towards investigating musical and vibrational frequencies as a treatment method of both disorders.
4. Muscle Relaxation
Clinical studies have demonstrated the efficacy of TENS to relieve neuropathic pain.6 Neuropathic pain is one of the hardest pain conditions to treat and medications used are often ineffective; TENS may offer a safer and cheaper alternative option.
Previous studies have reported that low frequency transcutaneous electrical nerve stimulation (LF-TENS) therapy helps decrease pain intensity and increase short form McGill Pain Questionnaire (SF-MPQ) scores among people living with fibromyalgia,8 rheumatoid arthritis9, chronic neck and shoulder pain5,6 or chronic headache pain5. Unfortunately, however, its exact mechanisms remain unknown; central nervous system pathways could possibly play a part.
Intramuscular mechanisms could play an integral role in low-frequency potentiation of force and membrane excitability in human muscle. Experiments conducted on plantar flexor muscles with different lengths revealed an increase in electrically evoked force during conditioning 100 Hz stimulation followed by immediate low frequency (2s) tetanus stimulation; this effect was eliminated after adding a 200ms pause after 100 Hz conditioning stimulation, suggesting it might be related to increased myofibrillar Ca2+ sensitivity.
Another series of experiments explored the effects of an interim, 100-ms pause between high-frequency and low-frequency stimulation, where force and [Ca2+]i measurements at intermediate muscle length were made in both cases. Force potentiation with or without the pause was similar, suggesting myosin light-chain phosphorylation may not play a major role in low frequency potentiation of human muscle; however, this does not exclude potential roles for sarcoplasmic reticulum Ca2+ dependent mechanisms.
5. Sleep
Studies have demonstrated the benefits of electromagnetic fields known as Schumann resonance to help induce sleep. A device emits 7Hz Schumann resonance frequency to enhance brainwave entrainment for improved insomnia symptoms and extended restful nights (see figure above).
One randomized controlled trial demonstrated how dorsolateral prefrontal cortex (DLPFC) rTMS improved nocturnal sleep for patients suffering chronic pain compared to control subjects who received sham coils (Pain Reduction with Neuromodulation in Post-Surgical Pain study). DLPFC rTMS led to significant reductions in time spent awake after sleep onset (WASO), improved overall efficiency as measured by Pittsburgh Sleep Quality Index questionnaires, and correlated positively with changes seen on Hamilton Rating Scale for Anxiety (HRSA), suggesting rTMS may help alleviate anxiety along with improving sleep.
Another randomized controlled trial explored the effect of DLPFC rTMS on patients suffering from both sleep disorder and major depressive disorder (MDD), who reported poor quality of life. After 10 sessions, DLPFC rTMS significantly decreased WASO in experimental group and improved PSQI score.
These trials involved relatively small sample sizes; to more reliably demonstrate these results, future research should include larger samples with longer follow up. Furthermore, it would be worthwhile to explore mental effects on more participants as well as explore its mechanism.
