{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,13]],"date-time":"2026-01-13T21:27:44Z","timestamp":1768339664071,"version":"3.49.0"},"reference-count":45,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2023,4,3]],"date-time":"2023-04-03T00:00:00Z","timestamp":1680480000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"swiss national fund","award":["SNF 32003B_173292-1"],"award-info":[{"award-number":["SNF 32003B_173292-1"]}]},{"name":"University of Basel","award":["SNF 32003B_173292-1"],"award-info":[{"award-number":["SNF 32003B_173292-1"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Toxins"],"abstract":"<jats:p>Local botulinum toxin (BTX-A, Botox\u00ae) injection in overactive muscles is a standard treatment in patients with cerebral palsy. The effect is markedly reduced in children above the age of 6 to 7. One possible reason for this is the muscle volume affected by the drug. Nine patients (aged 11.5; 8.7\u201314.5 years) with cerebral palsy GMFCS I were treated with BTX-A for equinus gait at the gastrocnemii and soleus muscles. BTX-A was administered at one or two injection sites per muscle belly and with a maximum of 50 U per injection site. Physical examination, instrumented gait analysis, and musculoskeletal modelling were used to assess standard muscle parameters, kinematics, and kinetics during gait. Magnetic resonance imaging (MRI) was used to detect the affected muscle volume. All the measurements were carried out pre-, 6 weeks post-, and 12 weeks post-BTX-A. Between 9 and 15% of the muscle volume was affected by BTX-A. There was no effect on gait kinematics and kinetics after BTX-A injection, indicating that the overall kinetic demand placed on the plantar flexor muscles remained unchanged. BTX-A is an effective drug for inducing muscle weakness. However, in our patient cohort, the volume of the affected muscle section was limited, and the remaining non-affected parts were able to compensate for the weakened part of the muscle by taking over the kinetic demands associated with gait, thus not enabling a net functional effect in older children. We recommend distributing the drug over the whole muscle belly through multiple injection sites.<\/jats:p>","DOI":"10.3390\/toxins15040267","type":"journal-article","created":{"date-parts":[[2023,4,4]],"date-time":"2023-04-04T01:35:59Z","timestamp":1680572159000},"page":"267","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["The Non-Affected Muscle Volume Compensates for the Partial Loss of Strength after Injection of Botulinum Toxin A"],"prefix":"10.3390","volume":"15","author":[{"given":"Reinald","family":"Brunner","sequence":"first","affiliation":[{"name":"Department of Paediatric Orthopaedics, University Children\u2019s Hospital Basel (UKBB), 4056 Basel, Switzerland"},{"name":"Laboratory of Movement Analysis, University Children\u2019s Hospital Basel (UKBB), 4056 Basel, Switzerland"},{"name":"Department of Biomedical Engineering, University of Basel, 4123 Allschwil, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1077-6294","authenticated-orcid":false,"given":"Enrico","family":"De Pieri","sequence":"additional","affiliation":[{"name":"Laboratory of Movement Analysis, University Children\u2019s Hospital Basel (UKBB), 4056 Basel, Switzerland"},{"name":"Department of Biomedical Engineering, University of Basel, 4123 Allschwil, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christian","family":"Wyss","sequence":"additional","affiliation":[{"name":"Laboratory of Movement Analysis, University Children\u2019s Hospital Basel (UKBB), 4056 Basel, Switzerland"},{"name":"Department of Biomedical Engineering, University of Basel, 4123 Allschwil, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-8272-3817","authenticated-orcid":false,"given":"Claudia","family":"Weidensteiner","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, University of Basel, 4123 Allschwil, Switzerland"},{"name":"Division of Radiological Physics, Department of Radiology, University Hospital Basel, 4031 Basel, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Katrin","family":"Bracht-Schweizer","sequence":"additional","affiliation":[{"name":"Laboratory of Movement Analysis, University Children\u2019s Hospital Basel (UKBB), 4056 Basel, Switzerland"},{"name":"Department of Biomedical Engineering, University of Basel, 4123 Allschwil, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jacqueline","family":"Romkes","sequence":"additional","affiliation":[{"name":"Laboratory of Movement Analysis, University Children\u2019s Hospital Basel (UKBB), 4056 Basel, Switzerland"},{"name":"Department of Biomedical Engineering, University of Basel, 4123 Allschwil, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Meritxell","family":"Garcia","sequence":"additional","affiliation":[{"name":"Department of Neuroradiology, University Hospital Z\u00fcrich, 8091 Z\u00fcrich, Switzerland"},{"name":"Division of Neuroradiology, Clinic for Radiology & Nuclear Medicine, University Hospital Basel, 4031 Basel, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2492-2048","authenticated-orcid":false,"given":"Norine","family":"Ma","sequence":"additional","affiliation":[{"name":"Orthopaedic Department, The Royal Children\u2019s Hospital, Melbourne 3052, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2292-0946","authenticated-orcid":false,"given":"Erich","family":"Rutz","sequence":"additional","affiliation":[{"name":"Orthopaedic Department, The Royal Children\u2019s Hospital, Melbourne 3052, Australia"},{"name":"Murdoch Children\u2019s Research Institute\u2014MCRI, Melbourne 3052, Australia"},{"name":"Department of Paediatrics, The University of Melbourne, Melbourne 3052, Australia"},{"name":"Medical Faculty, University of Basel, 4000 Basel, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,4,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"214","DOI":"10.1111\/j.1469-8749.1997.tb07414.x","article-title":"Development and reliability of a system to classify gross motor function in children with cerebral palsy","volume":"39","author":"Palisano","year":"1997","journal-title":"Dev. 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