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Fibromyalgia Syndrome & Surface Electromyography

Dynamic functional capacity and movement assessment via sEMG is a viable tool in treating patients with FMS.
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Fibromyalgia (FMS) was recognized as a true illness by the American Medical Association and as a major cause of disability in 1987. The American College of Rheumatology further clarified the illness in 1990 by identifying diagnostic criteria and stating "...the presence of unexplained widespread pain or aching, persistent fatigue, generalized morning stiffness, non-refreshing sleep, and multiple tender points."

FMS is defined as a painful, but not articular, condition predominantly involving muscles. It is known as the most common cause of chronic widespread musculoskeletal pain.1 Some of the more recent literature implies that FMS is a centrally mediated pain disorder and exists concurrently with Myofascial Pain (MFP). Patients with FMS/MFP are often incapable of performing even sedentary work in a vocational environment. In addition, key findings in patients with the medical diagnoses of FMS/MFP are the failure to recover from metabolic fatigue. This evidence substantiates the complex issues of physical dysfunction that is intrinsic to designing appropriate, safe and specific parameters of performing simple daily living tasks. Clearly FMS/MFP are debilitating syndromes.

There are numerous perpetuating factors of the concurrent FMS/MFP illnesses. There are three factors – behavioral, biomechanical and mechanical – that can be considered most common. Behavioral factors are those that include non-restorative (lack of stage IV phase) sleep, secondarily induced depression and anxiety, muscle abuse (from performance of actions beyond physiological ability) and repetitive motion. Biomechanical factors that are involved include vitamin inadequacy and other nutritional factors, hormonal dysfunctions, allergic conditions, impaired muscle metabolism and hypoglycemia. The third set of factors are those that are mechanical. These include asymmetrical use of body musculature, sensory changes, immobility (secondary to pain), prolonged inactivity, intrinsic chronic and persistent trigger points of MFP.

Assessment and Treatment with sEMG

Identifying and treating FMS/MFP can be accomplished through dy-namic functional movement assessment using Surface Electromyography (sEMG). It was first described in the mid-1800s and came into clinical use in the 1920s. However, many medical practitioners are still unfamiliar with this technology and its significance for soft tissue injury. Perpetuating factors in chronic pain through the appropriate quantification of muscle spasm and contracture, and the objective analysis of posture, movement and emotions, are strong considerations.

The assessment of functional movement potential not only aids in quantifying goals, it reflects and identifies spasm, hypertonicity, hypotonicity, protective guarding, somatic dysfunction, fasiculations, trigger points and contractures. Moreover, this objective measurement modality assists the rehabilitation practitioner in a patient's status and progress. SEMG has the ability, with Median Frequency Spectral Analysis (MFSA), to assess not only force fatigue but also metabolic fatigue and recovery time of the muscle, which is a critical component that relates to a variety of movement tasks. Dysfunctional movement patterns are also identified with sEMG, thus decreasing compensatory movement behaviors perpetuating pain.

SEMG is a primary complement to comprehensive medical and physical therapy evaluations. Given that it best records surface muscle groups, and can be correlated to needle EMG findings for trigger point activity, sEMG is valuable in the rehabilitation of patients with the following medical and physical therapy working diagnoses:

  • Muscle Injury or Spasm
  • Complicated Pain
  • Altered Motor Strategies
  • Myofascial Soft Tissue Restrictions
  • Incontinence Dysfunctions
  • General Decondition
The author checks the sEMG unit on physical therapy assistant, Bob Gilson.

Key Applications and Benefits of sEMG

  • The critical factors of muscle fatigue and recovery time in designing exercise programs are considered with sEMG MFSA.
  • Dysfunctional movement patterns from a variety of physiological causes can be assessed in viewing the firing patterns of muscles with trigger points. Asymmetrical utilization of muscle groups can be measured and treated appropriately.
  • Complicated musculoskeletal disorders have characteristic patterns of referred and compensatory muscle activity and trigger points. The negative impact on functional ability and outcomes can be adequately assessed, effectively and immediately treated, and often predicted with sEMG and MFSA.
  • The ability of a muscle to adequately contract is fundamental to any strengthening, endurance and skilled functional movement exercise program. SEMG can identify inappropriate responses to varying workloads, level of coordinated muscle skill and readiness to participate.
  • Repetitive motion and selective low frequency fatigue failure disorders have a pattern of onset, predictable course of compensation patterns and widespread muscular dysfunction with time. These patterns can be quantitatively documented with sEMG.
  • Muscles rated as normal strength in manual or isokinetic tests may not be recruited during movements in a variety of functional tasks. The resulting imbalances may perpetuate chronic dysfunction and pain. SEMG can document the physical therapy diagnosis and support the medical necessity for skilled intervention.
  • Patients respond positively to the feedback and resulting self efficacy in actively creating the changes that are possible and necessary in their functional daily activities.

Surface EMG also studies the energy of the soft tissue muscles and their related function. Studying the body's energy at this level, enables the practitioner to begin to see the contributions and perpetuating factors in chronic pain through objective quantification.2 Muscle function may be affected negatively by nociception and the response may be splinting rather than functional motion. Once the faulty muscle patterns have been identified via sEMG, it may be used as a measurement tool to track the effects of treatment or may be used as a tool itself with which to precipitate.3 Two major theses of sEMG biofeedback do exist; one is relaxation and the other is dynamic functional movement. SEMG can be enlisted periodically to reassess the status of the neuromuscular system following therapeutic endeavors including physical therapy or manipulations. Moreover, sEMG can quantify the functional capacity for an individual wishing to return to work.

Last updated on: May 16, 2011
First published on: September 1, 2000