Peter Wolf

Last Name

Wolf

First Name

Peter

ORCID

0000-0003-3616-9038

Organisational unit

03654 - Riener, Robert / Riener, Robert

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Publications 1 - 10 of 177

Roboterunterstützte RehaGames: Erfahrungen und Perspektiven
Wolf, Peter; Novak, Domen; Klamroth-Marganska, Verena; et al. (2014)
Neurologie & Rehabilitation
The perception of nested affordances: an examination of expert climbers
Seifert, Ludovic; Dicks, Matt; Wittmann, Frieder; et al. (2021)
Psychology of Sport and Exercise
Nested affordances in climbing comprise of multiple sequential actions, encompassing more than isolated reaching and grasping. This study examined the extent to which the perception of (multiple) nested affordances in climbing can be understood relative to body-scaled anthropometrics (arm span) and action-scaled (maximal action capabilities) measures, in relation to sequential task-goals of varying complexity. The utilisation of functionally equivalent actions during the actualisation of nested affordances was also investigated. Participants were required to estimate the maximal distance a handhold could be reached in four conditions of varying complexity: nested affordances (reach to Touch; reach to Grasp) vs. multiple nested affordances (reach to grasp with one hand followed by Removing the other hand from the starting handhold; reach to grasp with one hand followed by Moving up to another handhold). Ten expert climbers first had to estimate their maximal reaching distance in these different conditions (Touch, Grasp, Remove, Move Up) before performing the climbing movement. This sequence of estimation-action was repeated four times in each condition. Results revealed that action-scaling measures better captured nested affordances when multiple sequential behaviours are nested than body-scaled measures. Our findings also suggest that expert climbers utilise functionally equivalent movements during the realisation of multiple nested affordances (Remove and Move Up conditions).
Quantification of friction force reduction induced by obstetric gels
Riener, Robert; Leypold, Kerstin; Brunschweiler, Andreas; et al. (2009)
Medical & Biological Engineering & Computing
Development of a Textile Integrated, Two-State Controlled Tremor Suppression Orthosis for the Wrist
Fromme, Nicolas P.; Esser, Adrian; Camenzind, Martin; et al. (2023)
IEEE Transactions on Medical Robotics and Bionics
Tremor is one of the most common movement disorders with the highest prevalence in the upper limb. Apart from medication or surgery, the mechanical suppression of the involuntary movement with an orthosis can be used as alternative treatment. Here we propose a controlled energy dissipating suppression orthosis using a mechanical brake. For this approach, we focused on improved wearability with voluntary movement preservation and ergonomics while providing tremor suppression. The novelty of this orthosis is the decentralization of the tremor suppression mechanism and the integration of textiles in the orthosis structure. We performed computational and test bench simulations of a controlled two-state brake with a 1D human model to optimize the brake duration and timing. The objective was to optimize the trade-off between tremor suppression and voluntary movement suppression. The textile-integrated prototype, with the optimized parameter, was validated in a proof-of-concept case study with a tremor-affected person performing activities of daily living. With the optimized parameters, we achieved a tremor suppression of 78.8%, 66.5%, and 40.8% for the simulation, test bench, and case study, respectively as measured by the change in power spectral density (PSD) at the tremor frequency peak. While minimizing the voluntary movement suppression in the simulation and test bench by introducing the trajectory distance as new validation method (23.7% and 31.2%), no voluntary movements suppression was measured in the case study using PSD analysis. Our new orthosis has the potential to become a daily wearable device that can improve the quality of life for tremor-affected people.
Impact of a shoulder exosuit on range of motion, endurance, and task execution in users with neurological impairments
Esser, Adrian; Müller, Fabian; Manczurowsky, Julia; et al. (2025)
Wearable Technologies
The Myoshirt, an active exosuit, provides gravity compensation for the shoulders. This study evaluated the impact of the Myoshirt on range of motion (ROM), endurance, and activities of daily living (ADLs) performance through tests involving nine participants with varying levels of arm impairments and diverse pathologies. Optical motion capture was used to quantify ROM of the shoulder and elbow joints during isolated movements and functional tasks. Endurance was quantified through a timed isometric shoulder flexion task, and a battery of ADL tasks was used to measure the perceived support of the exosuit, along with changes in movement quality. Feedback and usability insights were gathered with surveys. The Myoshirt did not significantly improve ROM during isolated movements (shoulder flexion, shoulder abduction, and elbow flexion/extension), but during the reaching phase of a functional drinking task elbow extension increased significantly by 13.5% (t = 7.52, p = .002). Participants could also keep their arms elevated 78.7% longer (t = 1.942, p = .047). Patients also reported less perceived difficulty with ADLs while using the device, and a therapist reported improved execution quality. Participants who self-reported severe impairment levels tended to derive greater benefits compared to those with milder impairments. These findings highlight the potential of the Myoshirt as an assistive device, particularly for individuals with severe impairments, while emphasizing the need for further refinement.
Does a specific MR imaging protocol with a supine-lying subject replicate tarsal kinematics seen during upright standing?
Wolf, Peter; Stacoff, Alex; Liu, Anmin; et al. (2007)
Biomedical Engineering / Biomedizinische Technik
Antizipation der Schussrichtung beim Penalty
Miloradovic, Nina; Broggi, Simon; Riener, Robert; et al. (2010)
Unilaterale Sprunggelenksinstabilität
Mühl, Aline; Lorenzetti, Silvio; Wolf, Peter (2010)
Testen und Messen in der Sportwissenschaft : 2. Jahrestagung der SGS : 5. / 6. März 2010 in der Science City an der ETH Zürich : Abstract‐Band
Biomechanical effects of passive hip springs during walking
Haufe, Florian; Wolf, Peter; Riener, Robert; et al. (2020)
Journal of Biomechanics
Passive spring-like structures can store and return energy during cyclic movements and thereby reduce the energetic cost of locomotion. That makes them important components of the human body and wearable assistive devices alike. This study investigates how springs placed anteriorly across the hip joint affect leg joint angles and powers, and leg muscle activities during level walking at 0.5 to 2.1 m/s. We hypothesized that the anterior hip springs (I) load hip extension, (II) support hip flexion and (III) affect ankle muscle activity and dynamics during walking. Effects at the ankle were expected because hip and ankle redistribute segmental power in concert to achieve forward progression. We observed that the participants’ contribution to hip power did not increase during hip extension as the spring stored energy. Simultaneously, the activities of plantarflexor muscles that modulate energy storage in the Achilles tendon were reduced by 28% (gastrocnemius medialis) and 9% (soleus). As the spring returned energy with the onset of hip flexion, the participants’ contribution to hip power was reduced by as much as 23%. Soleus activity before push-off increased by up to 9%. Instead of loading hip extension, anterior hip springs seem to store and return parts of the energy normally exchanged with the Achilles tendon. Thereby, the springs support hip flexion but may reduce elastic energy storage in and hence recoil from the Achilles tendon. This interaction should be considered during the design and simulation of wearable assistive devices as it might – depending on user characteristics – enhance or diminish their overall functionality.
Validity and Reliability of Accelerometer-Based Gait Assessment in Patients with Diabetes on Challenging Surfaces
de Bruin, Eling; Hubli, Michèle; Hofer, Pamela; et al. (2012)
Journal of Aging Research
Walking on irregular terrain influences gait of diabetic patients. We investigate the test-retest reliability and construct validity of gait measured with the DynaPort MiniMod under single and dual task conditions in diabetic patients walking on irregular terrain to identify the measurement error (precision) and minimal clinical detectable change. 29 patients with Type 2 diabetes were measured once, and 25 repeated the measurement within 7 days. Patients walked on a therapy garden walkway. Differences between three groups of diabetics with various levels of lower extremity neuropathy were analyzed with planned contrasts. ICC was excellent for intervisit measurements with ICC's > 0.824. Bland and Altman Plots, SEM, and SDD showed precise values, distributed around zero for both test conditions. A significant effect of grouping on step length performance hints at possible construct validity of the device. Good reliability of DynaPort MiniMod measurements on a therapy garden walkway and an indication for discriminatory capability suggests that DynaPort MiniMod could facilitate the study of gait in diabetic patients in conditions close to real-life situations. Good reliability, small measurement error, and values of minimal clinical detectable change recommend the further utilization of DynaPort MiniMod for the evaluation of gait parameters in diabetic patients.

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