Ascending curbs of progressively higher height increases forward trunk flexion along with upper extremity mechanical and muscular demands in manual wheelchair users with a spinal cord injury

High upper extremity (U/E) demands are required when manual wheelchair users (MWUs) with spinal cord injury (SCI) ascend curbs; this may contribute to the risk of developing U/E musculoskeletal impairments. The aim of this study was to compare movement strategies (kinematics), mechanical loads (kinetics) and muscular demand (EMG) at the non-dominant U/E among 15 MWUs with SCI when ascending curbs of 4 cm (3 trials), 8 cm (3 trials) and 12 cm high (3 trials) from a starting line set 3 m before the curb. Biomechanical data was collected during three trials for each height. The curb ascent task was divided into three adjustment phases: caster pop, rear-wheel ascent and post-ascent. The greatest effort was generated by the shoulder flexors and internal rotators as well as the elbow flexors. A significant difference (p < 0.0167) between the curb heights was found for most outcome measures studied: movement excursion, net joint moments and muscular utilization ratio (MUR) of the main muscles increased with the higher curb heights, mainly around the shoulder joint. These results provide insight that aside from adhering to a highly structured training method for wheelchair curb ascent, rehabilitation professionals need to propose task-specific strength training programs based on the demands documented in this study and continue to advocate for physically accessible environments.     

Collagen scaffolds modified with collagen-binding bFGF promotes the neural regeneration in a rat hemisected spinal cord injury model

Nerve conduit is one of strategies for spine cord injury(SCI)treatment.Recently,studies showed that biomaterials could guide the neurite growth and promote axon regeneration at the injury site.However,the scaffold by itself was difficult to meet the need of SCI functional recovery.The basic fibroblast growth factor(bFGF)administration significantly promotes functional recovery after organ injuries.Here,using a rat model of T9 hemisected SCI,we aimed at assessing the repair capacity of implantation of collagen scaffold(CS)modified by collagen binding bFGF(CBD-bFGF).The results showed that CS combined with CBD-bFGF treatment improved survival rates after the lateral hemisection SCI.The CS/CBD-bFGF group showed more significant improvements in motor than the simply CS-implanted and untreated control group,when evaluated by the 21-point Basso-Beattie-Bresnahan(BBB)score and footprint analysis.Both hematoxylin and eosin(H&E)and immunohistochemical staining of neurofilament(NF)and glial fibrillary acidic protein(GFAP)demonstrated that fibers were guided to grow through the implants.These findings indicated that administration of CS modified with CBD-bFGF could promote spinal cord regeneration and functional recovery.     

Between-day reliability of MyotonPRO for the non-invasive measurement of muscle material properties in the lower extremities of patients with a chronic spinal cord injury

Measuring the muscle properties of patients with spinal cord injuries (SCIs) is important to better understand their biomechanical features. In this study, we sought to evaluate the between-day reliability of MyotonPRO, a handheld device that can measure muscle mechanical properties, and assess whether it is reliable to measure muscle properties over time in patients with SCI. Thirteen men with complete SCIs (age 53.9 ± 6.3 years, height 171.0 ± 5.2 cm, weight 66.1 ± 5.8 kg), and injury levels ranging from L1 to T12, were enrolled. Oscillation frequency; logarithmic decrement; dynamic stiffness; mechanical stress relaxation time; and creep of the biceps femoris, medial and lateral gastrocnemius, rectus femoris, tibialis anterior, and Achilles tendon were measured on consecutive days using MyotonPRO. The intraclass coefficient for most muscles and the Achilles tendon ranged from 0.53 to 0.99 for all parameters. The percentage standard error of the measurement for many parameters in most muscles and the Achilles tendon was less than 10%. Bland-Altman analysis showed a high agreement for all mechanical properties. No significant differences were observed in any muscle or Achilles tendon properties between days (all p > 0.05). These results indicate that the MyotonPRO is reliable for between-day measurements of the mechanical properties of lower limb muscles and Achilles tendon in patients with SCI.