Benefits of the Cybathlon 2020 experience for a prosthetic hand user: a case study on the Hannes system.

BACKGROUND: Cybathlon championship aims at promoting the development of prosthetic and assistive devices capable to meet users' needs. This paper describes and analyses possible exploitation outcomes of our team's (REHAB TECH) experience into the Powered Arm Prosthesis Race of the Cybathlon 2020 Global Edition, with the novel prosthetic system Hannes. In detail, we present our analysis on a concurrent evaluation conducted to verify if the Cybathlon training and competition positively influenced pilot's performance and human-technology integration with Hannes, with respect to a non-runner Hannes user. METHODS: Two transradial amputees were recruited as pilots (Pilot 1 and Pilot 2) for the Cybathlon competition and were given the polyarticulated myoelectric prosthetic hand Hannes. Due to COVID-19 emergency, only Pilot 1 was trained for the race. However, both pilots kept Hannes for Home Use for seven weeks. Before this period, they both participated to the evaluation of functionality, embodiment, and user experience (UX) related to Hannes, which they repeated at the end of the Home Use and right after the competition. We analysed Pilot 1's training and race outcomes, as well as changes in the concurrent evaluation, and compared these results with Pilot 2's ones. RESULTS: The Cybathlon training gradually improved Pilot 1's performances, leading to the sixth place with a single error in task 5. In the parallel evaluation, both pilots had an overall improvement over time, whereas Pilot 2 experienced a deterioration of embodiment. In detail, Pilot 1, who followed the training and raced the Cybathlon, improved in greater way. CONCLUSION: Hannes demonstrated to be a valuable competitor and to perform grasps with human-like behaviors. The higher improvements of Pilot 1, who actively participated in the Cybathlon, in terms of functionality, embodiment and UX, may depend on his training and engagement in the effort of achieving a successful user-prosthesis interaction during the competition. Tasks based on Cybathlon's ones could improve the training phase of a prosthetic user, stimulating dexterity, prosthetic integration, and user perception towards the prosthesis. Likewise, timed races or competitions could facilitate and accelerate the learning phase, improving the efficiency and efficacy of the process.

Psychometric analysis of the questionnaires for the assessment of upper limbs available in their Italian version: a systematic review of the structural and psychometric characteristics.

INTRODUCTION: There is no systematic review that analyzes the psychometric properties of questionnaires in Italian. Previous studies have analyzed the psychometric characteristics of instruments for the measurement of pathologies of upper limbs and their joints in different languages. The aim of the present study was to analyze the psychometric properties of the questionnaires published in Italian for the evaluation of the entire upper limb or some of its specific regions and related dysfunctions. EVIDENCE ACQUISITION: For the development of this systematic review, the following databases were used: PubMed, Scopus, Cochrane, Dialnet, Cinahl, Embase and PEDro. The selection criteria used in this study were: studies of transcultural adaptation to Italian of questionnaires oriented to the evaluation of upper limbs or any of their structures (specifically shoulder, elbow and wrist/hand), and contribution of psychometric variables of the questionnaire in its Italian version. EVIDENCE SYNTHESIS: After reading the titles and applying the inclusion and exclusion criteria to the complete documents, 16 documents were selected: 3 for the upper limb, 8 for the shoulder, 1 for the elbow and 4 for the wrist and hand. The cross-sectional psychometric variables show levels between good and excellent in all the questionnaires. Longitudinal psychometric variables had not been calculated in the vast majority of the analyzed questionnaires. CONCLUSIONS: Italian versions of the questionnaires show good basic structural and psychometric characteristics for the evaluation of patients with musculoskeletal disorders of the upper limb and its joints (shoulder, elbow and wrist/hand).

Pericardium matrix buttressing hinders the stapled bronchial stump healing.

BACKGROUND: Biomechanical and histological properties of stapled bronchi with and without bovine pericardial matrix plus collagen reinforcement are analyzed. MATERIALS AND METHODS: Pneumonectomy with mechanical bronchial suture was performed in the swine model. Pigs were randomly assigned to three groups: three-row staplers without reinforcement (Traditional), with reinforcement (Buttressed) and control "wild type", non-resected normal bronchus (Normal). Intraoperative test was carried for air leaks at 20/30/40 mm Hg endobronchial pressure. After 60 d, tracheobronchial specimen was harvested, stocked, and analyzed. Tensile test was performed using INSTRON 5965 loading frame machine. Maximal strain resistance value, length of elongation at rupture parameter, and stiffness coefficient (K) were evaluated. Histological analysis was performed. Sample size calculation was assessed (four per group), and the Student t-test was used to statistically evaluate differences in biomechanical variables. RESULTS: No fistula occurred. Biomechanical analysis showed that maximal strain resistance is 41.22 ± 2.11 N (Traditional), 24.53 ± 3.47 N (Buttressed), and 30.91 ± 0.29 N (Normal); elongation at rupture is 16.01 ± 1.82 mm (Traditional), 12.89 ± 0.48 mm (Buttressed), and 9.32 ± 0.11 mm (Normal). Finally, K is 2.59 ± 0.16 N/mm (Traditional), 1.91 ± 0.33 N/mm (Buttressed), and 3.32 ± 0.01 N/mm (Normal). Stumps without reinforcement proved higher resistance and length of elongation than reinforced ones. Normal bronchial tissue shows the highest stiffness coefficient. Statistical analysis produced significant values for each biomechanical feature. Group Buttressed stumps show greater thickness and a substantial inflammatory reaction with granulation tissue along the whole scar and around areas of discontinuity within the scar, not yet healed. CONCLUSIONS: Reinforcing the mechanical suture line of bronchial stump with bovine pericardial matrix plus collagen shows suboptimal biomechanical and histological characteristics compared to using the stapler alone.

Questionnaires for the evaluation of the cervical and lumbar spine in Italian language: a systematic review of the structural and psychometric characteristics.

INTRODUCTION: There has been an increase in the use of questionnaires as tools for the subjective evaluation of patients with neuro-musculoskeletal problems. The aim of this study was to analyze the psychometric properties of the questionnaires published in Italian for the evaluation of cervical and lumbar spine pain and related dysfunction. EVIDENCE ACQUISITION: Two blinded bibliographical searches were carried out on seven databases, regarding back, lumbar and/or cervical musculoskeletal problems. Both the structural characteristics and the psychometric aspects of each of the questionnaires were extracted from each of the selected articles. The structural characteristics were: full name, acronym, author and date of adaptation to the Italian language, what it measures, number of items, time to complete, the result scale, where the points are located and the cost. The psychometric aspects were: standard error of measurement (SEM), minimum detectable change (MDC), minimal clinically important difference (MCID), test-retest reliability, internal consistency, criterion validity, construct validity and sensitivity to changes. EVIDENCE SYNTHESIS: For the structural characteristics of the questionnaires identified for the valuation of the lumbar area, the number of items ranged between 10 and 24. Only two of the questionnaires presented specific categories, and the time to complete ranged between 5 and 7 minutes. The reliability of the questionnaires ranged between 0.869 and 0.961. None of the questionnaires calculated the inter-observer reliability. The internal consistency ranged between 0.82 and 0.90 for criterion validity. None of the questionnaires calculated sensitivity, SEM, MDC or MCID, with the exception of the Fear-Avoidance Beliefs Questionnaire, which showed a value of 12 on MDC. For the assessment of the cervical region, the number of items ranged from 6 to 20. Three of the questionnaires had sub-categories, and the time to complete them ranged between 2 and 5 minutes. The test-retest reliability ranged between 0.78 and 0.997. The internal consistency ranged between 0.842 and 0.942. CONCLUSIONS: The Italian versions of the questionnaires present good basic structural and psychometric characteristics for the evaluation of patients with back, lumbar and/or cervical musculoskeletal disorders. The analysis of the structural and psychometric characteristics of these questionnaires is fundamental to identify the best tools to use in research and in clinical practice.

Exploring the Embodiment of a Virtual Hand in a Spatially Augmented Respiratory Biofeedback Setting.

Enhancing the embodiment of artificial limbs-the individuals' feeling that a virtual or robotic limb is integrated in their own body scheme-is an impactful strategy for improving prosthetic technology acceptance and human-machine interaction. Most studies so far focused on visuo-tactile strategies to empower the embodiment processes. However, novel approaches could emerge from self-regulation techniques able to change the psychophysiological conditions of an individual. Accordingly, this pilot study investigates the effects of a self-regulated breathing exercise on the processes of body ownership underlying the embodiment of a virtual right hand within a Spatially Augmented Respiratory Biofeedback (SARB) setting. This investigation also aims at evaluating the feasibility of the breathing exercise enabled by a low-cost SARB implementation designed for upcoming remote studies (a need emerged during the COVID-19 pandemic). Twenty-two subjects without impairments, and two transradial prosthesis users for a preparatory test, were asked (in each condition of a within-group design) to maintain a normal (about 14 breaths/min) or slow (about 6 breaths/min) respiratory rate to keep a static virtual right hand "visible" on a screen. Meanwhile, a computer-generated sphere moved from left to right toward the virtual hand during each trial (1 min) of 16. If the participant's breathing rate was within the target (slow or normal) range, a visuo-tactile event was triggered by the sphere passing under the virtual hand (the subjects observed it shaking while they perceived a vibratory feedback generated by a smartphone). Our results-mainly based on questionnaire scores and proprioceptive drift-highlight that the slow breathing condition induced higher embodiment than the normal one. This preliminary study reveals the feasibility and potential of a novel psychophysiological training strategy to enhance the embodiment of artificial limbs. Future studies are needed to further investigate mechanisms, efficacy and generalizability of the SARB techniques in training a bionic limb embodiment.

Biomechanical analysis on total knee replacement patients during gait: Medial pivot or posterior stabilized design?

BACKGROUND: Total Knee Replacement surgery restores joint function in patients with advanced osteoarthritis. There are several prostheses available based on different mechanisms, which guarantee knee stability during Activities of Daily Living. The aim of this study is to compare ball-in-socket (or Medial Pivot) and post-cam mechanisms to detect possible differences in terms of biomechanical parameters between these two prosthesis designs and to evaluate which design is closer to physiological biomechanics. METHODS: A kinematics, kinetics and electromyography lower limb analyses were performed during gait on sixty subjects: twenty with Medial Pivot prosthesis, twenty with posterior stabilized prosthesis and twenty healthy subjects to obtain a physiologic reference. FINDINGS: Total Knee Replacement gait pattern for both patient groups were characterized by reduced walking speed, reduced stride length and increased stance time respect to control group. Comparison between Medial Pivot and Posterior Stabilized groups showed a reduction of knee flexion and flexor moment in patients with ball-in-socket mechanism. A prolonged muscular activity of rectus femoris was observed in Medial Pivot patients compared to Posterior Stabilized and control groups. INTERPRETATION: "Stiff knee pattern" mechanism was showed for both patient groups but more enhanced in Medial Pivot patients. Even though the Posterior Stabilized design introduces the non-physiological paradoxical motion and the Medial Pivot design seems to better reproduce the physiological condylar movement as gait analysis parameters, including kinematics, kinetics and electromyographic parameters were closer to control group and, in turn, to physiological gait for the Posterior Stabilized than Medial Pivot group parameters.

Shoulder joint loadings in post total hip replacement surgery patients during assisted walking: The influence of the crutch setup.

A crutch is prescribed to permit the patient to walk safely and independently immediately after total hip replacement (THR) surgery. Purpose of this study is to evaluate the influence of the crutch setup on upper limbs biomechanics, including shoulder joint kinematics and kinetics parameters that will be evaluated to detect possible differences related to the crutch length. Thirty patients were randomly assigned to elbow flexed (EF) or elbow extended (EE) forearm crutch setup. Subjects were asked to walk on the laboratory path, instrumented with motion tracking system and force platforms. Spatiotemporal gait parameters, crutch ground reaction force (GRF) and crutch displacement (measured as the relative distance between the crutch position on the floor and the shoulder joint center), were evaluated. A three-dimensional (3D) biomechanical model was implemented to determine shoulder joint kinematics and kinetics during crutch walking. Results showed that the stride length significantly decreased, and base of support width increased for the EF group when compared to the EE group. Crutch forces and distance to the body significantly decreased in the EE group. Furthermore, shoulder joint moments in all planes of motion, vertical and lateral forces were significantly reduced in the EE group. The present study showed that crutch setup influenced performance and upper limb loading during walking, with EE setup allowing a more stable walking and reducing stress on the shoulder joint when compared to the EF setup. Results may help therapists in rationalizing crutch length adjustments for patients after THR surgery.

The influence of the crutch setup on stability and weight-bearing parameters in post total hip replacement surgery patients during quiet standing.

PURPOSE: The purpose of this study is to evaluate the influence of the crutch setup on standing, in post total hip replacement (THR) surgery patients. MATERIALS AND METHODS: Thirty patients after THR were randomly assigned to walking with the elbow flexed (EF) or elbow straight (ES) crutch setup. Subjects were asked to stand on a force platform in a comfortable position with the crutch positioned on the unaffected side, facing forward for 10 seconds. Centre of pressure total path and maximal excursion were evaluated in both medio-lateral and anterior-posterior planes. Difference in the asymmetry of left/right acromial height, measured with and without the crutch, was calculated (ACdiff). Percentage of body weight borne by the crutch (Fcr), symmetry (SIload) between operated and healthy limbs loading during the trial, together with shoulder forces and moments were measured. RESULTS: No significant differences between the two groups (p > .05) were found for stability parameters. ACdiff, Fcr and shoulder load increased significantly (p < .05) in EF group compared to ES group. In addition leg loading symmetry was significantly reduced in the EF group. CONCLUSIONS: The present study showed that the ES setup reduced the force borne by the crutch, the load on the shoulder joint and it minimized postural and loading asymmetries when compared to EF setup. Conversely, postural stability was not influenced by the crutch setup. Implications for Rehabilitation Static posture and weight-bearing parameters are influenced by crutch setup during quiet standing. Crutch setup does not influence postural stability. Adjusting the crutch according to the elbow straight setup reduces the force borne by the crutch and the asymmetry in lower limbs loading. Forces and moments at the shoulder joint were reduced for the elbow straight setup group.

Does crutch length influence gait parameters after total hip replacement surgery?

After total hip replacement surgery, crutches are often prescribed to enable patients to walk independently. Purpose of this study was to evaluate possible crutch length influence on gait performance and symmetry, including spatiotemporal and kinetics parameters. Thirty patients were randomly assigned to elbow flexed (EF) or elbow extended (EE) crutch setup. Subjects were asked to walk on the laboratory path, instrumented with motion tracking system and force platforms. Spatiotemporal gait parameters and ground reaction force (GRF) parameters for both limbs and crutch support were evaluated. In addition, limb symmetry was evaluated for both gait and force parameters using the symmetry index. Variability was quantified for base of support width, stride time and length as the coefficient of variation. Results showed that cadence and walking speed were not significantly different, but stride length significantly decreased and base of support width increased for the EF group when compared to the EE group. Operated limb GRF parameters were significantly decreased for the EF group, while crutch force parameters decreased for the EE group. Furthermore, the EF group showed greater stride length variability and asymmetry of force and spatiotemporal parameters than EE group did. The results of the present study showed that EF and EE setups did not assist patients equally during walking, with EE setup allowing more load bearing on the operated side, reducing load on the crutch and asymmetries in gait parameters when compared to the EF setup. This may help clinicians in rationalizing crutch setup for patients after total hip replacement surgery.

Unassisted quiet standing and walking after crutch usage in patients with total hip replacements: Does crutch length matter?

BACKGROUND: Crutch use is prescribed early in the rehabilitation process following total hip replacement (THR) surgery to improve safety and promote return to active living. RESEARCH QUESTION: Purpose of this study was to understand mid-term effects of crutch length setup on quiet standing and walking two months post-op when crutch use was no longer required. METHODS: Thirty patients were evaluated 2 months post-surgery when they had been walking without crutch for a month. The patients had previously been assigned randomly to elbow flexed (EF) or elbow extended (EE) crutch set-ups and evaluated 3 days post-surgery. Quiet standing stability was assessed with participants standing in a comfortable position with each foot on separated force platforms, facing forward for 10 s. In addition, participants walked on the laboratory path, instrumented with motion tracking system and force platforms. For the quiet standing trial, centre of pressure measure, acromial height and lower limbs load bearing symmetry were evaluated. For the walking trial, spatiotemporal and ground reaction force (GRF) parameters were evaluated together with side symmetry indices. RESULTS: Results showed no significant differences in any standing trial variables between groups. For walking, GRF parameters and symmetry indices were similar for both groups. However, increased base of support width, reduced self-selected walking speed and stride length were found for the EF group. SIGNIFICANCE: This study showed that crutch set-up influenced gait after patients started to walk unassisted. Patients that previously used crutch adjusted according to the EE setup, demonstrated a more efficient gait with higher self-selected speed and longer and narrower stride. Clinicians may use these results for a proper crutch height adjustment, which improves walking and, in turn, functional recovery in post THR patients.

Biodegradable composite porous poly(dl-lactide-co-glycolide) scaffold supports mesenchymal stem cell differentiation and calcium phosphate deposition.

In recent decades, tissue engineering strategies have been proposed for the treatment of musculoskeletal diseases and bone fractures to overcome the limitations of the traditional surgical approaches based on allografts and autografts. In this work we report the development of a composite porous poly(dl-lactide-co-glycolide) scaffold suitable for bone regeneration. Scaffolds were produced by thermal sintering of porous microparticles. Next, in order to improve cell adhesion to the scaffold and subsequent proliferation, the scaffolds were coated with the osteoconductive biopolymers chitosan and sodium alginate, in a process that exploited electrostatic interactions between the positively charged biopolymers and the negatively charged PLGA scaffold. The resulting scaffolds were characterized in terms of porosity, degradation rate, mechanical properties, biocompatibility and suitability for bone regeneration. They were found to have an overall porosity of ∼85% and a degradation half time of ∼2 weeks, considered suitable to support de novo bone matrix deposition from mesenchymal stem cells. Histology confirmed the ability of the scaffold to sustain adipose-derived mesenchymal stem cell adhesion, infiltration, proliferation and osteo-differentiation. Histological staining of calcium and microanalysis confirmed the presence of calcium phosphate in the scaffold sections.

Biomechanical behaviour of native and sutured bronchi: An in-vitro study.

BACKGROUND: Biomechanical behaviour evaluation of a suture is an important information for the surgeon to choose the best technique to perform. OBJECTIVE: To assess the biomechanical behavior of the native and mechanically sutured bronchi. METHODS: Ten bronchi were harvested from slaughtered pigs and then randomly separated in two groups, a control intact group and a sutured group where specimens were cut in half and sutured, to evaluate mechanical properties during a tensile test using a loading frame machine. In addition optoelectric motion tracking system was used to evaluate suture profile motion during the test. RESULTS: Significant differences (p < 0.05) were found between the two groups for the parameters investigated. The control group showed a higher maximal stress resistance and stiffness than the suture group, while elongation at rupture was increased in the sutured group. All the sutures broke in symmetric manner, as the mean of the side difference of the sutured specimens was 0.93 ± 0.80 mm at rupture. CONCLUSIONS: Biomechanical behaviour of native and sutured bronchi was evaluated, giving highly reproducible parameters regarding mechanical properties that may help clinicians and bioengineers to rationalize the choice for a particular suture material or suture technique, increasing surgical outcomes.

Electromechanical delay of the knee flexor muscles after anterior cruciate ligament reconstruction using semitendinosus tendon.

The purpose of the study was to evaluate whether using only the semitendinosus as a tripled short graft would affect the electromechanical delay (EMD) of the knee flexors. EMD was evaluated in volunteers (N = 15) after they had undergone surgery for anterior cruciate ligament (ACL) reconstruction where the semitendinosus tendon alone was used as a graft. The results were compared with the intact leg and healthy controls (N = 15). After warming up, each subject performed four maximally explosive isometric contractions on an isokinetic dynamometer. Torques were measured by the dynamometer, while the electrical activity of the semitendinosus and biceps femoris muscles was detected using surface electromyography. EMD was found to be significantly increased (p = 0.001) in patients who had undergone ACL reconstruction compared to the controls. On the contrary, no significant differences (p = 0.235) were found for the biceps femoris muscle between the two groups. Similar results were found when the study group was compared with the intact leg group (p = 0.027 for semitendinosus and p = 0.859 for biceps femoris). Harvesting the semitendinosus tendon increases the EMD for the semitendinosus muscle but does not influence the EMD outcomes for the biceps femoris muscle.

Dynamic stability of the trunk during unstable sitting in people with low back pain.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To evaluate the dynamic stability and kinematics of the trunk during unstable sitting, and to determine the differences in these biomechanical parameters between healthy participants and participants with low back pain (LBP). SUMMARY OF BACKGROUND DATA: Patients with LBP exhibited alterations in trunk kinematics while performing different dynamic tasks and in static posture as a result of pain. It is not clear if changing in trunk motion may reduce postural control and the ability to perform a balancing task. METHODS: Twenty-three participants with LBP and 31 healthy participants were requested to sit on a custom-made swinging chair and to regain the balance after tilting the chair backward for 10° and 20°. Lumbar spine, pelvis, and chair motions were recorded using FASTRAK sensors. The thoracolumbar curvature of all participants was also evaluated in the standing position. The angular displacement of the chair was fitted in an equation describing the underdamped second-order response to a step input. RESULTS: Kinematic analysis showed that the hip range of motion increased whereas spine range of motion angle decreased in participants with LBP for both tilt angles (P < 0.05). There were no significant differences between the 2 subject groups in the time required to regain balance, and the natural frequency and damping ratio of the kinematic equation. Lumbar lordosis significantly decreased in LBP group. CONCLUSION: Participants with LBP showed trunk postural and movement adaptations that seems to be compensatory strategies to decrease the risk of further injuries and aggravation of the symptoms, but their ability to regain the balance was not affected by LBP. Clinicians should encourage patients with LBP to remain active while they are experiencing pain.

The role of trunk muscles in sitting balance control in people with low back pain.

The purpose of this study was to examine the muscular activities and kinetics of the trunk during unstable sitting in healthy and LBP subjects. Thirty-one healthy subjects and twenty-three LBP subjects were recruited. They were sat on a custom-made chair mounted on a force plate. Each subject was asked to regain balance after the chair was tilted backward at 20°, and then released. The motions of the trunk and trunk muscle activity were examined. The internal muscle moment and power at the hip and lumbar spine joints were calculated using the force plate and motion data. No significant differences were found in muscle moment and power between healthy and LBP subjects (p>0.05). The duration of contraction of various trunk muscles and co-contraction were significantly longer in the LBP subjects (p<0.05) when compared to healthy subjects, and the reaction times of the muscles were also significantly reduced in LBP subjects (p<0.05). LBP subjects altered their muscle strategies to maintain balance during unstable sitting, but these active mechanisms appear to be effective as trunk balance was not compromised and the internal moment pattern remained similar. The changes in muscle strategies may be the causes of LBP or the result of LBP with an attempt to protect the spine.

Stiffness properties of the trunk in people with low back pain.

The purpose of this study was to examine the dynamic properties of the trunk during unstable sitting and to determine differences between healthy and low back pain (LBP) participants. Participants sat on a custom-made chair that was able to swing freely in the sagittal plane. The chair was mounted on a force platform to measure loads acting at the trunk. Each participant was asked to find a balanced position after the chair was tilted backward and released. Movements of the trunk and chair were recorded. Effective moment of inertia, stiffness and damping coefficients were derived using a second order linear model. 10 participants were re-tested to assess reliability. Trunk stiffness was found increased for LBP subjects (p<.05) while no difference was found for damping coefficient. Gender and initial tilt angle did not affect viscoelastic properties of the spine. A second order linear model adequately described the biomechanical response of the trunk. It was shown that the trunk response was mainly elastic for all participants. The increase in trunk stiffness in LBP subjects could be a compensatory strategy to decrease pain and the risk of further injuries, but further investigations are needed to understand the nature of the viscoelastic alterations.