Cycle-to-cycle control of swing phase of paraplegic gait induced by surface electrical stimulation

Parameterised swing phase of gait in paraplegics was obtained using surface electrical stimulation of the hip flexors, hamstrings and quadriceps; the hip flexors were stimulated to obtain a desired hip angle range, the hamstrings to provide foot clearance in the forward swing, and the quadriceps to acquire knee extension at the end of the swing phase. We report on two main aspects; optimisation of the initial stimulation parameters, and parameter adaption (control). The initial stimulation patterns were experimentally optimised in two paraplegic subjects using a controlled stand device, resulting in an initial satisfactory swinging motion in both subjects. Intersubject differences appeared in the mechanical output (torque joint) per muscle group. During a prolonged open-loop controlled trial with the optimised but unregulated stimulation onsets and burst duration for the three muscle groups, the hip angle range per cycle initially increased above the desired value and subsequently decreased below it. The mechanical performance of the hamstrings and quadriceps remained relatively unaffected. A cycle-to-cycle controller was then designed, operating on the basis of the hip angle ranges obtained in previous swings. This controller successfully adapted the burst duration of the hip flexors to maintain the desired hip angle range.     

Length and moment arm of human leg muscles as a function of knee and hip-joint angles

Summary Lengths of muscle tendon complexes of the quadriceps femoris muscle and some of its heads, biceps femoris and gastrocnemius muscles, were measured for six limbs of human cadavers as a function of knee and hip-joint angles. Length-angle curves were fitted using second degree polynomials. Using these polynomials the relationships between knee and hip-joint angles and moment arms were calculated. The effect of changing the hip angle on the biceps femoris muscle length is much larger than that of changing the knee angle. For the rectus femoris muscle the reverse was found. The moment arm of the biceps femoris muscle was found to remain constant throughout the whole range of knee flexion as was the case for the medial part of the vastus medialis muscle. Changes in the length of the lateral part of the vastus medialis muscle as well as the medial part of the vastus lateralis muscle are very similar to those of vastus intermedius muscle to which they are adjacent, while those changes in the length of the medial part of the vastus medialis muscle and the lateral part of the vastus lateralis muscle, which are similar to each other, differ substantially from those of the vastus intermedius muscle. Application of the results to jumping showed that bi-articular rectus femoris and biceps femoris muscles, which are antagonists, both contract eccentrically early in the push off phase and concentrically in last part of this phase.     

Effect of maximal arm exercise on skin blood flux in the paralyzed lower limbs in persons with spinal cord injury

 The purpose of the present study was to examine the effect of maximal arm exercise on the skin blood circulation of the paralyzed lower limbs in persons with spinal cord injury (PSCI). Eight male PSCI with complete lesions located between T3 and L1 performed graded maximal arm-cranking exercise (MACE) to exhaustion. The skin blood flux at the thigh (SBFT) and that at the calf (SBFC) were monitored using laser-Doppler flowmeter at rest and for 15 s immediately after the MACE. The subject's mean peak oxygen uptake and peak heart rate was 1.41 ± 0.22 l · min^–1 and 171.6 ± 19.2 beats · min^–1, respectively. No PSCI showed any increase in either SBFT or SBFC after the MACE, when compared with the values at rest. These results suggest that the blood circulation of the skin in the paralyzed lower limbs in PSCI is unaffected by the MACE. Accepted: 12 September 1996     

Developmental regulation of type 1 and type 3 interferon production and risk for infant infections and asthma development

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Retroesophageal right subclavian artery with persistent ductus arteriosus

We report an adult male cadaver with persistence of the ductus arteriosus and a right retroesophageal artery. The retroesophageal artery was first appreciated as a retropharyngeal mass during the dissection of this area. Both the left and right vertebral arteries originated in normal fashion. The thoracic duct of our specimen drained into the junction of the left internal jugular and left subclavian veins. We believe this to be the first report of simultaneous right retroesophageal subclavian artery and patent ductus arteriosus. The anatomy and embryology of these two anomalies in the same specimen are discussed.     

Application of the medical anti-shock trouser (MAST) increases cardiac output and tissue perfusion in simulated,mild hypovolaemia

We have studied the haemodynamic effects of the application of the medical anti-shock trouser (MAST) in 10 healthy subjects in the semi-upright position in order to simulate mild hypovolaemia. Left ventricular end diastolic dimension (EDD) was measured by M-mode echocardiography and cardiac output (CO) by the Doppler ultrasound technique. Forearm blood flow (FBF) was measured by plethysmography and blood pressure (BP) by the standard cuff technique. Systematic increases in MAST pressure of up to 80 mm Hg were applied. EDD increased to a maximum of 9.3% (p0.01) which was associated with a maximum increase in CO of 31.7% (p0.05). FBF increased by a maximum of 54.2% (p0.001) whilst BP increased by a maximum of 12% (p0.001). These results demonstrate that the application of the MAST is an effective means of transferring blood to the central circulation by compression of the capacitance vessels resulting in significant increases in cardiac output and tissue perfusion. At high pressures there was evidence of compression of resistance vessels, which may be useful in reducing blood loss. The ease and rapidity with which his suit can be applied suggests that it may be useful in the short term treatment of hypovolaemia.     

The clinical utility of a decision-aid to facilitate the use of the hand in real-life activities of patients with distal radius fractures: A case study

BackgroundOccupation-based intervention (OBI) in hand therapy has shown superior benefits in patient-reported performance and physical measures; however, only a few studies have used OBI. We developed a decision-aid to promote the use of an injured hand in the real world (Aid for Decision-making in Occupation Choice for hand; ADOC-H)PurposeTo investigate the clinical utility of the ADOC-H (paper version) in patients with distal radius fractures.Study DesignA prospective case series and a clinical survey for occupational therapists.MethodsThis study comprised a prospective patient case series of 8 patients with distal radius fractures, treated using Volar locking plates, and a clinical survey of 4 experienced occupational therapists.ResultsNo patient or therapist complaints or drop-outs were reported. Active range of motion (wrist), Grip strength, and Disabilities of the Arm, Shoulder, and Hand scores improved for all patients. The ADOC-H induced 158 activities using the injured hand, with activities of daily living (69.8%) selected earlier in the treatment period, and instrumental activities of daily living (63.3%) selected later. The feedback and case studies suggested that the ADOC-H was useful for patients who were afraid of using the hand and, interestingly, patients who were able to use their hand without pain or other problems. The clinical survey showed that most therapists found the ADOC-H effective in facilitating real-life use of an injured hand.ConclusionsThe ADOC-H paper version is an useful tool that can be applied to facilitate patients with distal radius fractures to use their injured hands in real-life settings.     

Comparison of the outcomes of adipofascial and two–staged fasciocutaneous reverse sural flap in patients with lower leg trauma

BackgroundDistal one – third trauma of the lower limb is a complex condition to treat. The reverse sural flap is a time tested procedure for reconstruction of such defects especially in patients where free flaps are ruled out due to comorbidities. The purpose of this study is to compare the two modifications of the classical technique of reverse sural flap (adipofascial and fasciocutaneous) which is lacking in the literature.Material & methodsIn this study, the authors conducted a retrospective analysis of 67 patients with lower one-third leg defects reconstructed with either adipofascial reverse sural flap (Group A, n = 37) or two-staged fasciocutaneous reverse sural flap (Group B, n = 30) in a tertiary care hospital in North India between 2015 and 2019. An evaluation of the different flap characteristics of the two variants of the reverse sural flap was done and compared. Mean follow up period was 12 months.ResultsThe adipofascial group showed shorter operative time, was a single-stage and with better reach and aesthetic outcome. The complications did not differ except that for the adipofascial group was associated with unstable skin graft over the flap initially which did not require any treatment.DiscussionLower one-third defect of the lower limb has been a challenge for reconstructive surgeons all over the world. The goal of reconstruction is a functional lower limb. Although free tissue transfer is the preferred modality of treatment of such cases but it may not be possible in all cases due to various reasons. Reverse sural flap is a very lucrative local option for such reconstructions as it is easy to perform, reliable, low profile and bulk, require minimal facilities with less operative time. Adipofascial flaps represent an extremely useful modification of the reverse sural flap which is quick to perform with minimal donor site morbidity.ConclusionAdipofascial reverse sural artery flap is a good option for patients with lower limb trauma with the added advantage of being single-stage and with better donor site cosmesis as compared to the fasciocutaneous reverse sural artery flap.