Vladimir Janda


Abberant Firing of Gluteus Maximus After Injury

The likely influence of a localised injury in a distal joint on the function of proximal muscles is an important consideration in assessment and treatment of musculoskeletal injuries. However, little experimental evidence in humans exists in this area. Accordingly, a controlled study was carried out, in which the function of muscles at the hip was compared between subjects who had suffered previous severe unilateral ankle sprain and matched control subjects. The pattern of activation of the gluteus maximus, the hamstring muscles and the ipsilateral and contralateral erector spinae muscles was monitored through the use of surface electromyography during hip extension from prone lying. Analyses revealed that the pattern of muscle activation in subjects with previous injury differed markedly from normal control subjects, and that changes appeared to occur on both the uninjured and the injured sides of the body. A significant difference between the two groups was the delay in onset of activation of the gluteus maximus in previously injured subjects. The existence of remote changes in muscle function following injury found in this study emphasise the importance of extending assessment beyond the side and site of injury.

Proprioceptive Exercises Increase Injuried Muscle Activity

Gluteal activation and pelvic stability often are decreased in chronic low-back pain sufferers, but the importance of motor control and programming in treatment has not been fully evaluated. This study investigated whether gluteal muscles could be activated more effectively by stimulating the proprioceptive mechanism during walking. Labile support, through wearing "balance shoes," offered facilitation of cerebellovestibular circuits. Electromyographic recordings of gluteus maximus and medius in 15 healthy subjects were made during barefoot and balance shoes walking before and after 1 week of facilitation. Significant increases (P < 0.0002) in gluteal activity and significant decreases (P < 0.01) in time to 75% maximum contraction, demonstrated the value of sensorimotor elicitation of subconscious and automatic responses in muscles often weakened in back pain sufferers.

Other References


Postural Evaluation Of The Muscular System Through Visual Inspection

Through skilled visual inspection, the practitioner can access detailed information about the patient's muscular system that would otherwise be lost. Muscle and motor system dysfunctions lead to observable changes in muscle contour, muscle tone, and posture. Thorough analysis of the muscular system is doubly important because the close functional interdependence among the muscles, the osteoarticular and central nervous system regulation of movement. The muscles both cause and reflect altered function in these areas. A protocol for evaulation of the patient's muscular system in standing is presented and correlation made to potential changes in the articular system as well as in movement patterning.

A correction of the table entitled Muscles Prone to Tightness or Weakness is provided below:

Muscles Prone to Tightness 
  1. Gastrocnemius 
  2. Soleus 
  3. Tibialis Posterior 
  4. Short Hip Adductors 
  5. Hamstrings 
  6. Rectus Femoris 
  7. Iliopsoas 
  8. Tensor Fasciae Latae 
  9. Piriformins 
  10. Erector Spinae 
  11. Quadratus Lumborum 
  12. Pectoralis Major 
  13. Upper Trapezius 
  14. Levator Scapulae 
  15. Sternocleidomastoid 
  16. Scaleni 
  17. Flexors of Upper Limb 
  18. Masticatories 
  Muscles Prone to Weakness 
  1. Peronei 
  2. Tibialis Anterior 
  3. Vastus Medialis and Lateralis 
  4. Gluteus Maximus, Medius and Minimus 
  5. Rectus Abdominis 
  6. Serratus Anterior 
  7. Rhomboids 
  8. Middle and Lower Trapezius 
  9. Deep Neck Flexors 
  10. Digastricus 
  11. Extensors of Upper Limb