Chest Wall Kinematics and Respiratory Muscle Action During Supine Breathing in Individuals With and Without Spinal Cord Injury
Condition: Spinal Cord Injury
MeSH terms: Spinal Cord Injuries; Wounds and Injuries
Study type: Observational

Summary: 
      Objective: To investigate the movement strategy of breathing based on three-compartment model
      measured by optoelectronic plethysmography (OEP) and electromyography (EMG ) among
      individuals with and without spinal cord injury in supine posture during deep inspiration.

      Design: cross sectional repeated-measure with age matched control group. Setting: Motion
      Analysis Laboratory Participants: Seven tetraplegic and five paraplegic subjects and twelve
      age matched healthy controls were recruited.

      Intervention: Not applicable.
    

Detailed description: 
      Main Outcome Measures: The volume changes of chest wall and respiratory electromyographic (
      EMG ) muscle activity were measured simultaneously by OEP and surface EMG. The variables
      included volume changes (ΔV ), ratio of volume changes (ΔVr ), peak velocity of volume
      changes ( PV ), the percentage of peak velocity occurs ( PPV ) in three compartments (upper
      thorax, UT; lower thorax, LT; and abdominal compartment, AB), and Root Mean Square EMG ( RMS
      EMG ) of sternocleidomastoid and diaphragm (combined with intercostalmuscles).

      Results: Ttetraplegic individuals had smallerΔVUT andΔVLT than those of control subjects(P<
      .006 and .006, respectively). Furthermore, the ΔVr of AB was greater than those of UT and LT(
      P< .006, .006, respectively), PVAB was smaller than PVLT ( P< .006), PPVUT was greater than
      PPVLT and PPVAB ( P< .008, .008, respectively ). The paraplegic subjects had smallerΔVLT than
      that of control subjects ( P< .006 ). ΔVr of UT was greater than that of LT, and both PVUT
      and PVAB were greater than PVLT ( P< .006 and .006, respectively). However, the paraplegic
      subjects preferred to all three compartments to achieve the maximal inspiration, like control
      group. In control group, onlyΔVAB was comparable with other compartments. ΔVr of UT was
      greater than LT, and PVUT was greater than PVLT and PVAB ( P<.006 and .006, respectively).
      For the RMS EMG, it demonstrated that average RMS EMG of two muscles in both tetraplegic and
      paraplegic group were greater than that in control group (P< .017 and .017, respectively).

      Conclusion: The results applied the three-compartment model of chest wall to investigate the
      breathing pattern by OEP in individuals with and without SCI during inspiration of vital
      capacity breathing in supine posture. There were some interesting findings that (1) the
      tetraplegic subjects used AB contributed most volume changes, they can expand the AB more
      easily, and the UT took the responsibility to performed the final adjust during the
      inspiration; (2) the paraplegic subjects used UT contributed the most volume changes, they
      expanded the both UT and AB more easily, and all three compartment moved together during the
      inspiration; (3) the control subjects used UT to increase the most volume changes, they can
      expand UT more than the others, and all three compartments moved together during the
      inspiration phase, (4) the results of RMS EMG showed that the central neural drive in both
      tetraplegic and paraplegic subjects were greater than control group.
    

Observational model: Case-Control
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        community sample
      
Keywords: kinematic analysis,; three-compartment model,; chest wall motion,; spinal cord injury.