Exploring exercise participation and the usability of the adaptive rower and arm crank ergometer through wheelchair users' perspectives.

PURPOSE: Arm crank ergometry and adaptive rowing are existing exercise options for wheelchairs users, but not commonly available. This study was conducted to explore exercise participation of wheelchair users, as well as the usability of the adaptive rowing ergometer (aROW) and arm crank ergometer (ACE). METHODS: This mixed-methods study used a concurrent triangulation design. Following completion of both exercise sessions (5 min each), participants (n = 14) with spinal cord injury/disease (SCI/D) completed the System Usability Scale (SUS), and a semi-structured interview. Participants were asked about the use of both exercise modalities, and general exercise participation. SUS data were analyzed using a paired sample t-test and qualitative data were analyzed through conventional content analysis. RESULTS: Wheelchair users exercised for improved physical and mental health, as well as for functional independence, and community participation; however, lack of accessible equipment was a prominent barrier. Both the aROW and ACE have high usability, but the aROW was perceived as more enjoyable and effective for cardiovascular exercise. CONCLUSIONS: The implementation of the aROW into community gyms has the potential to help close the existing gap in inclusive equipment and may help people with disabilities to be more fully included in their community and lead healthier lives.Implications for rehabilitationWheelchair users perceive exercise as a meaningful activity that enhances physical health and risk of disease, functional independence, community participation, and overall social and emotional health.The adapted rowing machine was perceived as highly usable and was felt to be more enjoyable and effective for cardiovascular exercise compared to traditional arm crank ergometers.The adaptive rower provides an additional accessible equipment option for wheelchair users to obtain effective cardiovascular exercise.More available equipment may increase community participation and promote inclusion for wheelchair users.

Effects of NGF, NT-3 and GDNF family members on neurite outgrowth and migration from pelvic ganglia from embryonic and newborn mice.

BACKGROUND: Pelvic ganglia are derived from the sacral neural crest and contain both sympathetic and parasympathetic neurons. Various members of the neurotrophin and GDNF families of neurotrophic factors have been shown to play important roles in the development of a variety of peripheral sympathetic and parasympathetic neurons; however, to date, the role of these factors in the development of pelvic ganglia has been limited to postnatal and older ages. We examined the effects of NGF, NT-3, GDNF, neurturin and artemin on cell migration and neurite outgrowth from explants of the pelvic ganglia from embryonic and newborn mice grown on collagen gels, and correlated the responses with the immunohistochemical localization of the relevant receptors in fixed tissue. RESULTS: Cell migration assays showed that GDNF strongly stimulated migration of tyrosine hydroxylase (TH) cells of pelvic ganglia from E11.5, E14.5 and P0 mice. Other factors also promoted TH cell migration, although to a lesser extent and only at discrete developmental stages. The cells and neurites of the pelvic ganglia were responsive to each of the GDNF family ligands--GDNF, neurturin and artemin--from E11.5 onwards. In contrast, NGF and NT-3 did not elicit a significant neurite outgrowth effect until E14.5 onwards. Artemin and NGF promoted significant outgrowth of sympathetic (TH+) neurites only, whereas neurturin affected primarily parasympathetic (TH-negative) neurite outgrowth, and GDNF and NT-3 enhanced both sympathetic and parasympathetic neurite outgrowth. In comparison, collagen gel assays using gut explants from E11.5 and E14.5 mice showed neurite outgrowth only in response to GDNF at E11.5 and to neurturin only in E14.5 mice. CONCLUSION: Our data show that there are both age-dependent and neuron type-dependent differences in the responsiveness of embryonic and neo-natal pelvic ganglion neurons to growth factors.

Effects of pharmacological inhibition of small GTPases on axon extension and migration of enteric neural crest-derived cells.

In the developing enteric nervous system, there is a close association between migrating neural crest-derived cells and the axons of early differentiating neurons. We used pharmacological inhibitors of small GTPases to determine if crest cell migration and axon growth could be uncoupled in cultured intact explants of embryonic mouse gut and slices of embryonic gut grown on collagen gels containing GDNF. Inhibition of the Rho effectors, ROCKI/II, or Rac/Cdc42 inhibited both cell migration and neurite growth in intact explants of embryonic gut. The effects of both ROCKI/II and Rac/Cdc42 inhibitors were more severe on cell migration and axon extension in gut explants from Ret(+/-) mice than in explants from wildtype mice, indicating that Rho GTPases probably act downstream of the receptor tyrosine kinase, Ret. Inhibition of ROCKI/II had different effects on migration and axon extension in gut slices grown on collagen gels containing GDNF from that seen in intact explants of gut. We conclude that ROCKI/II and Rac/Cdc42 are required for both neural crest-derived cell migration and axon growth in the developing gut.

Characterization of lacZ-expressing cells in the gut of embryonic and adult DbetaH-nlacZ mice.

In mice that express lacZ under the control of a human dopamine beta-hydroxylase gene promoter (DbetaH-nlacZ mice), the nuclei of enteric neurons express the transgene, as shown by the presence of beta-galactosidase (beta-gal) staining (Mercer et al. [1991] Neuron 7:703-716). The transgene is also expressed by neural crest-derived cells in the developing gut before their differentiation into neurons or glial cells (Kapur et al. [1992] Development 116:167-175). However, the cell types expressing the DbetaH-nlacZ transgene within the developing and adult gut have not been fully characterized. Whole-mount preparations of embryonic and adult gut were processed for histochemistry or immunohistochemistry to reveal beta-gal plus markers of undifferentiated neural crest cells (in embryos) or enteric neurons (in adults). In embryonic mice, over 90% of undifferentiated neural crest-derived cells (identified using antibodies to p75) were beta-gal(+). Importantly, crest-derived cells at the migratory wavefront were all beta-gal(+). In adult mice, only a subpopulation of enteric neurons was beta-gal(+), while glial cells showed no beta-gal staining. Considerable variation was observed between the small intestine and colon in the proportion of myenteric neurons that showed beta-gal staining. We examined whether known classes of enteric neurons varied in their expression of DbetaH-nlacZ. In the myenteric plexus of the jejunum and colon, large calretinin(+) neurons did not express lacZ, suggesting that the incomplete penetrance of the DbetaH-nlacZ transgene observed in adult mice is not random. We conclude that the DbetaH-nlacZ transgene provides a reliable marker for examining the colonization of the developing gut by neural crest cells. However, in adult mice, there is variation between mice, between gut regions, and between different classes of enteric neurons in the expression of the transgene.