The aim was to describe diaphragmatic behavior during postural limb activities and examine the ventilatory and stabilizing functions of the diaphragm. Thirty healthy subjects were examined in the supine position using a dynamic MRI system assessed simultaneously with specialized spirometric readings. The diaphragmatic excursions (DEs) were measured at three diaphragmatic points in the sagittal plane; the diaphragm positions (DPs) as related to a reference horizontal baseline were determined. Measurements were taken during tidal breathing (TB) and isometric flexion of upper or lower extremities against external resistance together with TB. Mean DE in both upper and lower postural limb activities was greater compared with the TB condition (P < 0.05), with the effect greater for lower limb activities. Inspiratory DPs in the upper and lower extremity activities were lower compared with TB alone (P < 0.01). Expiratory DP was lower only for lower extremity activities (P < 0.01). DP was most affected at the apex of the crescent and crural (posterior) portion of the diaphragm. DEs correlated strongly with tidal volume (Vt) in all conditions. Changes in DEs relative to the initial value were minimal for upper and lower extremities but were related to lower values of Vt (P < 0.03). Significant involvement of the diaphragm in the limb postural activities was found. Resulting DEs and DPs differed from the TB conditions, especially in lower extremity activities. The differences between the percent changes of DEs vs. Vt found for lower extremity activities were confirmed by both ventilatory and postural diaphragm recruitment in response to postural demands.

DRA and LBP may be interrelated, especially among men. This may be a function of greater BMI in individuals with chronic LBP. Understanding the association between DRA, LBP, and BMI may have important implications for treatment of LBP and for intervention.

Study design: A questionnaire survey. Objectives: To evaluate the need for the introduction of quantitative diagnostic criteria for the traumatic central cord syndrome (TCCS). Setting: An online questionnaire survey with participants from all over the world. Methods: An invitation to participate in an eight-item online survey questionnaire was sent to surgeon members of AOSpine International. Results: Out of 3340 invited professionals, 157 surgeons (5%) from 41 countries completed the survey. Whereas most of the respondents (75%) described greater impairment of the upper extremities than of the lower extremities in their own TCCS definitions, symptoms such as sensory deficit (39%) and bladder dysfunctions (24%) were reported less frequently. Initially, any difference in motor strength between the upper and lower extremities was considered most frequently (23%) as a 'disproportionate' difference in power. However, after presenting literature review findings, the majority of surgeons (61%) considered a proposed difference of at least 10 points of power (based on the Medical Research Council scale) in favor of the lower extremities as an acceptable cutoff criterion for a diagnosis of TCCS. Most of the participants (40%) felt that applying a single criterion to the diagnosis of TCCS is insufficient for research purposes. Conclusion: Various definitions of TCCS were used by physicians involved in the spinal trauma care. The authors consider a difference of at least 10 motor score points between upper and lower extremity power a clear diagnostic criterion. For clinical research purposes, this diagnostic criterion can be considered as a face valid addendum to the commonly applied TCCS definition as introduced by Schneider et al.