According to Travell and Simons’, a trigger point is a “hyperirritable spot within skeletal muscle fibers that can sometimes develop in fascia, ligaments and surrounding joint capsules”. Trigger points shorten the affected tissue (Figure 1) and have predictable pain patterns. Causes can vary from postural imbalances, over use, inactivity, trauma, nutritional deficiencies, chronic infection, and psychological stress and/or sleep deprivation.1 The presence of a trigger point reduces the ability of a muscle group to function to its full potential because some of its fibers are locked together. Moderate activity will likely cause fatigue, weakness and irritation.1 In areas where a sensory nerve is caught within the trigger point, numbness, burning and abnormal sensation may occur thus can be mistaken for neuropathies and conditions like sciatica.1
Figure 1. Muscle Trigger Points
Clinical features
Myofascial trigger points are not identifiable using diagnostic tools1 such as an X-ray, ultrasound or MRI which help differentiate other conditions; accurate palpation is therefore essential. They can be active, latent or satellite in nature. Active trigger points cause local and radiating pain noticeable during daily activities.1 The gluteus minimus trigger point for example, found on the side of the buttock will refer pain and numbness to the hip, leg and ankle.2 Patients with this trigger point may also present with weakness standing on the affected side because of inability of the muscle to contract effectively.1
A latent trigger point goes undetected until compressed.1,2 Pectoralis minor muscle on the chest is a good example of this. Latent trigger points do not actively refer pain but if not addressed can cause chronic muscle tightness2 leading to secondary complications such as kyphosis (a hunching or rounding of the back).
Satellite trigger points develop in muscles compensating for those affected by active trigger points.1 The pain pattern of a satellite trigger point mirrors that of an active trigger.1
Treatment
Once identified, a trigger point is treated through pressure.1 Both the practitioner and patient can identify a trigger point from its tautness and associated symptoms.1 Massage techniques must be applied on the most painful spot to be effective.1 Low level intensity laser then enhances circulation and lymphatic fluid drainage3 to the local area thus flushing out metabolic wastes that would have accumulated in the muscle knot. Laser Therapy would also increase metabolic activity within the region of treatment accelerating the muscle’s ability to function effectively.3 Postural re-education, ergonomic advice, and stretches are tools with which a LaserHealth® therapist would be happy to assist you.