• Neuromuscular response (central activation ratio), characteristics of gait (stride length, step length, etc.), joint moments [ Time Frame: All study visits up to day 21 ] [ Designated as safety issue: No ]
  

• Characteristics of gait (stride length, step length, etc.) [ Time Frame: All study visits up to day 21 ] [ Designated as safety issue: No ]
  
• Orthopedic special tests and questionnaires [ Time Frame: Concluding at day 21 ] [ Designated as safety issue: No ]
  

It is well known that musculoskeletal dysfunction at one joint is not limited to the joint itself and can be related to dysfunction at joints proximal or distal in the kinetic chain. Recent research has focused on the relationship of altered lower extremity kinematics and common musculoskeletal pathologies.

Pain is often associated with musculoskeletal pathologies and is one of the strongest stimuli affecting functional activities in a negative manner. Following injury or chronic dysfunction, inhibitory neurons decrease the ability of musculature to fully recruit excitatory motor neurons. This can lead to aberrant movement patterns and different activation of muscles. Muscle inhibition has been attributed as a possible source of altered motor activation patterns. Pain can be a result or cause of musculoskeletal dysfunction and does not necessarily precede inhibition, but can have a contributing effect. The presence of muscle inhibition is considered a limiting factor in the rehabilitation of musculoskeletal pathologies. If muscle inhibition is properly addressed, individuals and athletes alike, should be able to more appropriately meet the demands of the activities with a decreased risk of future injury.

One technique used to determine presence of muscle inhibition is to measure the ability of the muscle to produce a maximal voluntary isometric contraction and compare values with the ability of the contralateral muscle. Since the contralateral limb may also experience muscle inhibition,it is difficult to obtain an accurate measurement of the amount of muscle inhibition occurring in the ipsilateral limb. A suggested solution is utilize the burst-superimposition technique which provides the muscle with a supramaximal stimulus to recruit any remaining muscle fibers which have not been stimulated.

Treatment of muscle inhibition is multifaceted. Utilization of manual therapy techniques such as joint manipulation or mobilization directed at the lumbopelvic region have been shown to be successful in disinhibiting lower extremity muscles. Previous studies have demonstrated sacroiliac joint manipulation disinhibited the quadriceps muscle in individuals with anterior knee pain. One of the limitations was these studies only observed an immediate decrease of quadriceps inhibition and the duration of the treatment effect was unknown. Effects of disinhibition of other lower extremity muscles and duration of disinhibition have not been determined at this time. It is also unknown what effects manual therapy treatments directed at the lumbopelvic region have on functional activities such as walking, squatting, or ascending/descending stairs. By examining these effects, we will be attempting to provide scientific evidence to validate common clinical practices in rehabilitative medicine.

Inclusion Criteria:

• Physician referral to physical therapy for treatment of insidious onset of lumbopelvic or lower extremity musculoskeletal dysfunction or individuals with chronic lumbopelvic or lower extremity musculoskeletal dysfunction not wishing to seek physical therapy services.

  • Unilateral or Bilateral hip pain or dysfunction
  • Unilateral or Bilateral knee pain or dysfunction with two of the following symptoms:

• Pain reproduced with patella compression, squatting, prolonged sitting, going up or down stairs, or isometric quadriceps contraction.

  • Unilateral or Bilateral ankle pain or dysfunction
  • Lumbopelvic pain or dysfunction
• Control subjects who volunteer in response to advertisements will have healthy, pain free, back, hips, knees, and ankles.

Exclusion Criteria:

• Participants who are outside of age range (to ensure bony maturity while reducing the prevalence of age related degenerative changes and hypomobility.)

• Participants with knee pain which does not fit inclusion criteria.

  • Ligamentous insufficiency, meniscus damage, patellar tendonitis, history of subluxation/dislocation

• Participants with signs indicating nerve root compression (contraindication for lumbopelvic joint manipulation)

  • Pain extending below knee
  • Positive Straight Leg Raise
  • Decreased lower extremity manual muscle test (Below 4/5), decreased sensation, hyporeflexia

• Participants demonstrating upper motor neuron signs (contraindication to lumbopelvic manipulation)

  • Hyperreflexia
  • Pathological reflexes
• Participants who have had lower extremity or spine surgery
• Participants who are unable to run for 5 minutes.
• Participants with ankylosing spondylitis (contraindication for lumbopelvic manipulation)
• Participants with spinal hypermobility or spondylolisthesis. (contraindication for lumbopelvic manipulation)
• Participants with spinal cord disease or cauda equina. (contraindication for lumbopelvic manipulation)
• Participants with osteoporosis. (contraindication for lumbopelvic joint manipulation)
• Participants with rheumatoid arthritis. (contraindication to lumbopelvic joint manipulation.)
• Participants who may be currently pregnant. (contraindication for electrical stimulation and lumbopelvic joint manipulation.)
• Participants with traumatic spine or lower extremity injury within past 6 months
• Participants who are currently participating or have participated in a lower extremity musculoskeletal rehabilitation program within the past 6 months.
• Participants who have had previous adverse reactions to electrical stimulation (i.e. electrode burns.)
• Participants who have a demand-type cardiac pacemaker (contraindication for electrical stimulation)
• Participants with diagnosis of cancer (current cancer is a contraindication for electrical stimulation and relative contraindication for lumbopelvic joint manipulation)
• Participants who are unable to give consent or are unable to understand procedures of experiment.