{"doi":"10.21203/rs.2.23757/v2","title":"Indirect measurement of anterior-posterior ground reaction forces using a minimal set of wearable inertial sensors: From healthy to hemiparetic walking","abstract":"Abstract Background: The anterior-posterior ground reaction force (AP-GRF) and propulsion and braking metrics derived from the AP-GRF time series are indicators of locomotor function across healthy and neurological diagnostic groups. In this paper, we describe the use of a minimal set of wearable inertial measurement units (IMUs) to indirectly measure the AP-GRFs generated during healthy and hemiparetic walking. Methods: Ten healthy individuals and five individuals with chronic post-stroke hemiparesis completed a 6-minute walk test over a walking track instrumented with six forceplates while wearing three IMUs securely attached to the pelvis, thigh, and shank. Subject-specific models driven by IMU-measured thigh and shank angles and an estimate of body acceleration provided by the pelvis IMU were used to generate indirect estimates of the AP-GRF time series. Propulsion and braking point metrics (i.e., peaks, peak timings, and impulses) were extracted from the IMU-generated time series. Peaks and impulses were expressed as % bodyweight (%bw) and peak timing was expressed as % stance phase (%sp). A 75%-25% split of 6-minute walk test data was used to train and validate the models. Indirect estimates of the AP-GRF time series and point metrics were compared to direct measurements of the same made by the reference standard forceplates. Results: Indirect measurements of the AP-GRF time series strongly approximated the direct measurements made by forceplates, with low error and high consistency in both the healthy (RMSE = 4.5 %bw; R2 = 0.93) and post-stroke (RMSE = 2.65 %bw; R2 = 0.90) cohorts. In the healthy cohort, the average errors between indirect and direct measurements of the peak propulsion magnitude, peak propulsion timing, and propulsion impulse point estimates were 2.37 %bw, 0.67 %sp, and 0.43 %bw. In the post-stroke cohort, the average errors for these same point estimates were 1.07 %bw, 1.27 %sp, and 0.31 %bw. Average errors for the braking-related point estimates were higher, but comparable. Conclusions: Accurate estimates of the AP-GRF time series and key propulsion and braking point metrics can be generated using three strategically mounted IMUs and subject-specific calibrations. This study is a foundational step toward the development of point-of-care diagnostic systems that can catalyze the routine assessment and management of propulsion and braking locomotor deficits during rehabilitation.","journal":"Research Square","year":2020,"id":128086,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9511,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":470659,"name":"Andre Alvarez","orcid":null,"position":1,"is_corresponding":false},{"id":276923,"name":"Conor J. Walsh","orcid":"0000-0002-2744-917X","position":2,"is_corresponding":false},{"id":469867,"name":"Stefano Rossi","orcid":"0000-0001-9800-3784","position":3,"is_corresponding":false},{"id":276919,"name":"Louis N. Awad","orcid":"0000-0002-0159-8011","position":4,"is_corresponding":false},{"id":276921,"name":"Dheepak Arumukhom Revi","orcid":"0000-0002-6943-0258","position":0,"is_corresponding":true}],"reference_count":72,"raw_metadata":null,"created_at":"2026-07-18T23:15:38.879956Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}