BACKGROUND:Pressure ulcers (PUs) are a common and serious secondary complication in individuals with spinal cord injury (SCI). Effective treatment strategies are crucial for improving patient outcomes. However, it remains unclear whether inpatient or outpatient treatment leads to better healing outcomes. STUDY DESIGN:Retrospective cohort study. OBJECTIVE:This study aimed to compare the healing progression of PUs grade 2 in SCI patients in the inpatient versus outpatient setting. SETTING:Spinal Cord Injury Centre, Balgrist University Hospital, Zurich, Switzerland. METHODS:Data from SCI patients treated for PUs between July 2017 and July 2019 were analysed retrospectively. Wound characteristics, localization, and healing progression were recorded for PUs grade 2. The primary outcome was the time to complete wound healing, analysed by localization and treatment setting. Kaplan-Meier survival analysis and the log-rank test were used to compare healing times between inpatient and outpatient treatment. RESULTS:Healing times varied by care setting. The mean time to complete healing was significantly reduced for inpatient care compared to the outpatient setting (median: 34 vs. 60 days; 95% CI 51.2 to 137.8 vs 30.2 to 63.1; p < 0.05). Kaplan-Meier analysis confirmed significantly shorter median healing times in the inpatient group (34 days; 95% CI: 27.2 to 57.4) compared to the outpatient group (69 days; 95% CI: 30.2 to 111.4; log-rank test, p = 0.014). CONCLUSION:The study highlights the importance of care setting in PU management, with inpatient treatment of PUs grad 2 leading to significantly faster healing than outpatient care.
STUDY DESIGN:Prospective multicenter cohort study. OBJECTIVES:To evaluate the association between the number of fused levels and clinical outcomes following posterior cervical fusion for degenerative cervical myelopathy (DCM). SETTING:Multicenter registry study in Japan. METHODS:Data from a prospective multicenter cervical spine surgery registry were analyzed. Seventy-seven patients with DCM who underwent posterior cervical fusion and completed 2-year follow-up were included. Patients were stratified by the number of fused levels: 1 level (n = 27), 2-3 levels (n = 34), and ≥4 levels (n = 16). Clinical outcomes included cervical JOA score, VAS, SF-36, NPSI, and JOACMEQ. Cervical alignment and range of motion were radiographically evaluated. RESULTS:Cervical alignment was similar among groups, whereas postoperative cervical ROM was significantly reduced in the ≥4-level group (p = 0.011). No significant differences were observed in JOA, SF-36, NPSI, or VAS outcomes. However, a lower JOACMEQ cervical function effectiveness rate was observed in groups with more fusion levels (p = 0.004). Perioperative complication rates were comparable across groups. CONCLUSION:Although a greater number of fused levels was associated with reduced patient-perceived cervical function, no significant between-group differences were observed in neurological recovery, pain relief, or overall quality of life. These findings support preoperative counselling regarding postoperative cervical function when multilevel fusion is clinically indicated. However, because fusion length was determined according to clinical indications in this observational study, residual confounding by indication cannot be excluded, and the findings should be interpreted cautiously.
Spinal cord injury (SCI) carries one of the highest disability weights among conditions tracked in the WHO's Global Burden of Disease framework, yet federal research investment remains skewed toward locomotor restoration rather than the secondary complications-bowel and bladder dysfunction, autonomic dysreflexia, pressure injuries, and neuropathic pain-that people with chronic SCI consistently identify as their greatest daily burden. Drawing on patient perspectives, a systematic funding analysis, and two decades of survey data, this piece shows that SCI receives approximately 0.2% of NIH funding against roughly 1% of U.S. disease burden, and that within SCI research itself, movement/mobility studies (2017-2023) drew nearly twice the funding allocated to pain, bladder, bowel, and pressure-injury research combined. This misalignment persists despite a 2004 survey establishing that the functional priorities of people living with SCI diverge sharply from prevailing research goals. Secondary complications are argued to warrant treatment as primary research targets rather than downstream concerns, alongside compounding structural barriers: a shortage of trained SCI physiatrists, underpowered and poorly reproducible preclinical models, and inconsistent translation of lived-experience data into funding decisions. Researchers, clinicians, and advocates are called upon to realign scientific priorities, clinical training, and policy with the actual burden of chronic SCI, closing a gap that has persisted largely unaddressed for over twenty years.
STUDY DESIGN:Cross-sectional observational cohort study OBJECTIVES: To investigate differences in executive function (EF) in adults with spinal cord injury (SCI) compared with able-bodied (AB) controls across tasks imposing varying levels of executive demand, and to examine implications for targeted cognitive screening. SETTING:Two SCI units in New South Wales (SCI), Australia, and the community of New South Wales, Australia (able-bodied). METHODS:Executive function was assessed in 40 adults with acute SCI and 32 AB controls using the Neuropsychiatry Unit Cognitive Assessment Tool (NUCOG). Two multivariate analyses of covariance (MANCOVA) were conducted to compare group performance across tasks requiring higher-order EF processes and tasks characterised by minimal EF demand, controlling for age, sex, and years of education. RESULTS:A significant multivariate group difference was observed across EF tasks, with individuals with SCI demonstrating significantly lower performance on categorical fluency, abstraction, and Digit Span Reverse following correction for multiple comparisons. No significant group differences were observed across tasks characterised by minimal EF demand. CONCLUSION:Adults with SCI exhibit selective impairments in higher-order executive functioning that emerge under increased cognitive demand, while performance on low-demand tasks remains relatively preserved. These findings highlight the importance of assessing EF components at the task level and support the need for targeted screening approaches sensitive to higher-order executive deficits to optimise rehabilitation outcomes.
STUDY DESIGN:Retrospective cohort study. OBJECTIVES:To evaluate the long-term risk of heart failure (HF) following spinal cord injury (SCI) and to determine whether the risk differs by anatomical injury level. SETTING:Korean National Health Insurance and National Health Screening Program databases (2012-2023). METHODS:Newly diagnosed SCI cases from 2015 to 2023 were identified using ICD-10 codes after a 3-year washout period. Each patient with SCI was matched to 20 controls using propensity scores based on demographic, lifestyle, and metabolic variables. Incident HF was defined by at least two ICD-10 I50 records within one month. Incidence rate ratios (IRRs) and adjusted hazard ratios (aHRs) were estimated using stratified Cox models accounting for matched sets. RESULTS:A total of 1412 patients with SCI (879 cervical; 572 thoracic/lumbar) and matched controls were included. Crude HF incidence rates per 1000 person-years were 10.25 for overall SCI and 10.76 for cervical SCI. IRRs were elevated for overall SCI (1.77; 95% CI, 1.36-2.29). In fully adjusted models, HF risk was increased for overall SCI (aHR 1.75; 95% CI, 1.13-2.71) and cervical SCI (aHR 2.12; 95% CI, 1.26-3.59), while thoracic/lumbar SCI showed a nonsignificant trend. Risks were highest among individuals aged ≥ 60 years and men with cervical SCI. Kaplan-Meier curves demonstrated lower HF-free survival across all SCI groups. CONCLUSIONS:SCI was associated with an elevated long-term risk of HF, particularly among those with cervical injuries and older adults. These findings underscore the need for enhanced cardiovascular monitoring and early preventive strategies in high-risk SCI populations.
STUDY DESIGN:Narrative review and data-based perspective OBJECTIVES: Compare the current literature on poly(ADP-ribose) (PAR) polymerase (PARP) inhibition and NAD+ supplementation in spinal cord injury (SCI) and determine the effectiveness of both treatment paradigms in improving pathophysiological outcomes induced by SCI in mice. METHODS:Using a spinal cord contusion mouse model, a severe SCI was induced at the L1 spinal level in female C57Bl/6 J mice. 25 mg/kg PARP inhibitor (Veliparib), 750 mg/kg NR, or vehicle was administered intraperitoneally starting at 1 h post-injury (n = 13-18 mice per group), followed by daily treatments up to 8 days post-injury, and every other day thereafter until sacrifice (28 days post-injury). Functional recovery (by Basso Mouse Scale, BMS) and tissue-level effects were evaluated. RESULTS:Functional recovery, lesion size (demyelinated (MBP), astrocyte (GFAP), and inflammatory (IBA1) area), and DNA damage load (γH2AX and PAR) did not improve with either Veliparib or NR treatment compared to vehicle-treated animals. Moreover, NR treatment decreased survival and increased astrogliosis in SCI mice compared to the vehicle control group. CONCLUSIONS:Within the experimental paradigm, neither PARP inhibition nor NAD+ supplementation improved major pathophysiological outcomes associated with an SCI. The results are reviewed in the context of previous reports using PARP inhibition or NAD+ supplementation strategies in SCI. At present, caution is recommended when considering these clinical modalities in treating SCI, and priorities to identify the best therapeutic paradigms are presented.
STUDY DESIGN:Single-institution retrospective study. OBJECTIVES:To evaluate postoperative neurological and QOL outcomes in patients with cauda equina tumors using JOABPEQ, and to investigate age-related differences in postoperative recovery, which remain poorly understood in this population. SETTING:Single university hospital. METHODS:Sixty-five patients who underwent surgery for cauda equina tumors from 2008-2017 were retrospectively analyzed. Neurological function was assessed using the JOA score, and QOL was evaluated using JOABPEQ before surgery and at two years postoperatively. Pain and sensory symptoms were assessed using VAS scores. Patients were categorized into elderly (≥65 years) and non-elderly (<65 years) groups. General linear models and multivariable logistic regression analyses were performed. RESULTS:Significant postoperative improvements were observed in JOA score, VAS scores, and all JOABPEQ domains. JOABPEQ demonstrated relatively high effectiveness rates in pain-related and physical function domains, whereas mental health showed the lowest effectiveness rate. Improvement in lower-limb numbness was independently associated with better recovery in walking ability, social life function, and mental health. Elderly patients showed worse preoperative neurological and pain-related symptoms; however, postoperative outcomes and JOABPEQ effectiveness rates were comparable between elderly and non-elderly patients after adjustment for cardiovascular disease and baseline severity. CONCLUSION:Surgical treatment for cauda equina tumors resulted in significant improvements in neurological function, pain, and QOL. Despite worse preoperative symptoms, elderly patients achieved postoperative outcomes comparable to those of non-elderly patients after adjustment for baseline factors. These findings support the usefulness of PROM-based evaluation in patients with cauda equina tumors.
STUDY DESIGN:Systematic review and meta-analysis. OBJECTIVES:To systematically evaluate the prevalence of diabetes mellitus (DM) among individuals with spinal cord injury (SCI), assess the association between SCI and DM compared with non-SCI populations, and synthesize evidence on associated factors within SCI populations. METHODS:Observational studies from PubMed, Embase, Cochrane Library, CINAHL, and ProQuest Dissertations & Theses Global, published up to August 2025 were identified. Two reviewers independently screened articles, extracted data, and assessed study quality using the Newcastle-Ottawa Scale (NOS) and the Agency for Healthcare Research and Quality (AHRQ) criteria. Heterogeneity was assessed using the I2 statistic, and sensitivity, subgroup, and publication bias analyses were conducted. RESULTS:Ten studies with 76,062 individuals with SCI were included, comprising six cohort and four cross-sectional studies. The pooled prevalence of DM among individuals with SCI was 12% (95% CI, 5-20%). SCI was associated with an approximately two-fold higher odds of DM compared with non-SCI populations (OR = 2.03, 95% CI, 1.30-3.16). Subgroup analyses suggested that study region and sample size contributed to heterogeneity in prevalence estimates. Within SCI populations, meta-analysis identified male sex (OR = 1.22, 95% CI, 1.05-1.40) and Black race (OR = 1.62, 95% CI, 1.24-2.10) as significant associated factors with DM. CONCLUSIONS:These findings highlight the importance of systematic DM screening, risk-stratified management, and integration of metabolic monitoring into long-term SCI care, while underscoring the need for large, prospective, and geographically diverse studies.
STUDY DESIGN:Retrospective data analysis. OBJECTIVES:Nearly half of all individuals with spinal cord injury (SCI) develop a pressure injury (PI). Surgical interventions are often unavoidable, creating a substantial economic burden. Electrical stimulation (ES) may help to prevent PIs by supporting skin perfusion and muscle tissue maintenance. This study provides an economic evaluation of healthcare costs comparing surgical PI treatment and preventive ES in people with SCI treated within the Swiss healthcare setting. SETTING:SCI Rehabilitation Centre in Switzerland. METHODS:We retrospectively analysed healthcare costs for individuals with chronic SCI and denervated gluteal muscles who developed a PI requiring surgical intervention. These costs were compared with projected expenses for preventive ES aimed at preserving muscle tissue and reducing PI risk. Included patients had been treated or had attended follow-up visits at a specialised acute and rehabilitation clinic for SCI in Switzerland between January 2021 and December 2024. RESULTS:Across 53 cases, median total surgical treatment costs (Q1-Q3) were of 143,309 Swiss Francs (CHF) (93,548-223,939), while the median hospital length of stay was of 89 (63-126) days. Indirect operating costs represented the largest component of expenses. In contrast, the projection of costs for twenty years of ES therapy was approximately 12,609 CHF, indicating substantial cost savings. CONCLUSIONS:Preventive ES represents a cost-saving alternative to surgical treatment of PIs in individuals with SCI in Switzerland. Its implementation could decrease healthcare expenditures, improve patient quality of life by reducing prolonged hospitalisations and bed rest. This further supports its consideration regarding regional reimbursement and clinical policies.
STUDY DESIGN:A descriptive cross-sectional study. OBJECTIVES:To investigate the experiences of Turkish women with spinal cord injury (SCI) in terms of contraception, fertility and pregnancy. SETTING:Inpatient and outpatient clinics of a tertiary referral hospital in Türkiye. METHODS:Seventy women (aged 18-55 years) with SCI were included. A comprehensive questionnaire containing questions about contraception, fertility, and obstetric experiences was administered. RESULTS:Among participants using a method of contraception (45.7%), the most frequently used method was condom (used by partner) (43.8%). The most common reason for choosing the contraceptive method used was that they thought the method of contraception they were using was safe (37.5%). The most common reason reported for not using a method of contraception was no longer being sexually active (55.3%). 68.6% of participants had completed family planning by the time they were diagnosed with SCI. 72.9% of participants had never discussed fertility-related issues with their physician before. Fifteen births were identified in participants with SCI. Of these 15 births, only 1 (6.67%) was vaginal, while 14 (93.33%) were by cesarean section. Of the 14 births performed via cesarean section, regional anesthesia was used in 5 (35.71%) and general anesthesia in 9 (64.29%). CONCLUSIONS:This study summarizes the experiences of Turkish women with SCI regarding contraception, fertility, and pregnancy. By drawing attention to these issues, the study may contribute to increased awareness among clinicians about the reproductive health of women with SCI.
STUDY DESIGN:Prospective, nationwide, multicenter observational cohort registry with first-year implementation data. OBJECTIVES:To describe the design and rationale of the Italian Spine Trauma Registry (TVMit) and assess the feasibility of standardized nationwide recruitment and longitudinal data collection in surgically treated spinal trauma. SETTING:Forty-eight neurosurgical centers across Italy. METHODS:Adults aged ≥ 16 years undergoing surgery for traumatic spinal column and/or spinal cord injury are prospectively enrolled from 2025 to 2034. Standardized data include demographics, injury characteristics, neurological status, surgical timing and technique, perioperative management, complications, rehabilitation, and Patient-Reported Outcome Spine Trauma (PROST), with follow-up at 3, 12, and 24 months. RESULTS:During the first year, 673 participants were enrolled. Lumbar injuries were most frequent (46.2%), followed by thoracic (30.6%), subaxial cervical (15.0%), and upper cervical injuries (8.0%). Surgery within 48 h was more frequent for subaxial cervical injuries (46.5%), and posterior approaches predominated at upper cervical, thoracic, and lumbar levels. CONCLUSIONS:TVMit has established a feasible national prospective platform for standardized real-world data collection in surgically managed spinal trauma. Longitudinal neurological and patient-reported outcomes will support benchmarking, comparative effectiveness research, and future predictive modeling.
STUDY DESIGN:Retrospective cohort study. OBJECTIVES:To identify sex- and age-stratified cutoff values of the upper extremity motor score (UEMS) that discriminate independent clean intermittent catheterization (CIC) acquisition and to examine whether UEMS assessed at 4 weeks post-injury predicts CIC acquisition in individuals with motor-complete spinal cord injury (SCI). SETTING:A specialized spinal cord injury center in Japan. METHODS:We included individuals with traumatic motor-complete SCI (American Spinal Injury Association Impairment Scale [AIS] A/B) hospitalized ≥4 weeks and classified as AIS A/B at discharge (n = 194). UEMS was assessed in 194 individuals at discharge and in 153 individuals at 4 weeks post-injury. The outcome was independent CIC at discharge. Participants were stratified by sex and age (<65 vs ≥65 years). UEMS cutoffs at discharge and 4 weeks were derived using receiver operating characteristic analyses, and area under the curve (AUC) was reported. RESULTS:Independent CIC was acquired by 91/194 (47%). Discharge UEMS cutoffs (AUC) were: males <65, 19 (0.97); males ≥65, 28 (0.97); females <65, 24 (0.95); females ≥65, 50 (0.96). At 4 weeks, corresponding cutoffs (AUC) were 13 (0.98), 23 (0.96), 19 (1.00), and 47 (0.90), in the same order. Study-specific equivalent motor levels corresponding to each UEMS cutoff were C6/C7/C6/T1 at discharge and C5/C6/C6/T1 at 4 weeks. CONCLUSIONS:UEMS yielded sex- and age-specific thresholds with good-to-excellent discrimination for CIC acquisition in traumatic motor-complete SCI. UEMS at 4 weeks may support early prediction of CIC acquisition by discharge; study-specific equivalent motor levels may aid interpretation.
STUDY DESIGN:Investigator-initiated, single-arm, first-in-human pilot study. OBJECTIVES:To evaluate the safety and feasibility of intramedullary administration of polymerized laminin in individuals with acute complete spinal cord injury (SCI). SETTING:Public and private hospitals in Brazil. METHODS:Eight patients with acute traumatic SCI classified as AIS A (C4-T12) were enrolled within days after injury (mean 2.3 days). Polymerized laminin was administered as a single intramedullary dose (1 µg/kg; total 55-80 µg). Patients were followed for 12 months using standardized neurological, laboratory, and neurophysiological assessments. RESULTS:Intramedullary administration was uneventful in all cases. No neurological deterioration or serious adverse events attributable to the intervention were observed. Mild laboratory abnormalities were transient and not associated with hepatic or renal toxicity. Three participants died during follow-up. Deaths were reviewed by the Brazilian National Research Ethics Commission (CONEP) and an external clinical consultant, and were not considered related to the intervention. Neurological improvement of at least two AIS grades was observed in six participants, including one who died after progressing to AIS C. Improvements in motor and/or somatosensory evoked potentials were observed in three patients. CONCLUSIONS:Intramedullary administration of polymerized laminin was uneventful and appeared to be safe in this small and heterogeneous cohort. Although the study design does not allow conclusions regarding efficacy, it provides proof-of-concept for this therapeutic approach and justifies further evaluation in controlled clinical studies. The study was initiated in December 2016, prior to current requirements for prospective trial registration.
STUDY DESIGN:Systematic Review. OBJECTIVES:To evaluate the clinical safety and efficacy of local hypothermia in the management of acute spinal cord injury. SETTING:The studies included in this review were conducted in Canada, the USA, and the UK. METHODS:A comprehensive search of PubMed, Embase, and Web of Science was conducted for studies up to December 2024, in accordance with PRISMA guidelines. Our inclusion criteria encompassed human patients with ASCI treated with local hypothermia and reported neurological outcomes. A random-effects single-arm meta-analysis was used to calculate pooled neurological improvement rates. RESULTS:Five studies comprising 48 patients were included. The pooled proportion of patients who experienced neurological improvement following local hypothermia was 54.4% (95% CI: 39.9-68.2%) with no significant heterogeneity (I² = 0%). Subgroup analyses did not detect statistically significant differences in outcomes based on injury level (cervical vs thoracic), time to cooling (<8 vs ≥8 h), or cooling route (intradural vs extradural), although these analyses were likely underpowered. Reporting of complications was variable, with infections, decubitus ulcers, and respiratory complications being the most prevalent. CONCLUSION:Local hypothermia may represent a potential adjunctive neuroprotective strategy for acute spinal cord injury, with over half of patients demonstrating neurological improvement in this limited dataset. However, these findings are hypothesis-generating and should be interpreted with caution. Variability in study protocols and limited sample sizes preclude definitive conclusions. Larger, standardized clinical trials and improved methods of local delivery of hypothermia are warranted to validate its therapeutic potential and optimize treatment parameters.
STUDY DESIGN:Retrospective cohort study. OBJECTIVES:To examine whether frailty, assessed using the 5-factor modified frailty index (mFI-5), predicts pneumonia and other complications in older adults with cervical spinal cord injury (CSCI). SETTING:A university-affiliated tertiary care hospital in Japan. METHODS:Data from 94 adults aged ≥65 years who were treated for CSCI were retrospectively reviewed. Frailty was defined as mFI-5 score ≥2. Patients were classified into frail (mFI-5 ≥ 2) and non-frail (mFI-5 < 2) groups. Logistic regression analyses were performed to evaluate associations between frailty and the incidence of complications, infections, and pneumonia. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Model performance was assessed using receiver operating characteristic analysis. RESULTS:Frailty was identified in 19% of patients. Overall, 45% of patients experienced complications, 37% developed infections, and 23% developed pneumonia. The frail group demonstrated significantly higher rates of complications, infections, and pneumonia compared with the non-frail group. In the multivariate analyses, frailty independently predicted pneumonia (OR: 6.8, 95% CI: 2.0-26) and infections (OR: 8.7, 95% CI: 2.1-45). Frailty, alongside high neurological injury level, was associated with an increased overall risk of complications. Predictive models demonstrated acceptable discriminatory ability for complications and infections. CONCLUSIONS:Frailty, assessed using the mFI-5, is an independent predictor of pneumonia and infections in older adults with CSCI. Early assessment of frailty may facilitate perioperative risk stratification, targeted preventive strategies, and informed clinical decision-making in this high-risk population. SPONSORSHIP:This work was supported by the Jikei University Research Fund.
Through a structured engagement initiative, the North American Spinal Cord Injury Consortium (NASCIC) consolidated perspectives from individuals with traumatic cervical spinal cord injury (SCI) regarding recovery priorities and the impact of functional gains on daily life. This exploratory outreach effort utilized the NASCIC network to capture community insights with respect to the development of targeted SCI therapies. The group represented a diverse range of lived experiences, with a median time since injury of 12 years (range 4-38). The group distribution (60% AIS A; 40% AIS B) ensured that insights captured the specific challenges of both complete and incomplete high-cervical injuries. Hand/arm function, bowel/bladder control, and trunk stability consistently emerged as top priorities, with participants emphasizing that even small improvements in these areas can be transformative for independence, caregiver burden, and emotional well-being. These insights challenge the traditional regulatory, clinician, and academic focus regarding large, functionally transformative improvements as the sole marker of clinical benefit. The findings support adopting a broader, participant-centered definition of clinically meaningful improvement in SCI and the use of outcome measures that reflect real-world priorities. Barriers to clinical trial participation and evolving expectations post-injury further highlight the need for patient-centered outcome measures and ethical, accessible trial design. Prioritization of participant-centered endpoints and addressing practical barriers to clinical trial participation should be considered in future research.
STUDY DESIGN:Retrospective cohort study. OBJECTIVES:To evaluate the association between appendicular skeletal muscle mass index (ASMI) and minimal clinically important difference (MCID)-defined motor recovery in patients with paraplegia due to spinal cord injury (SCI), and to identify ASMI thresholds associated with MCID-defined motor recovery. SETTING:Single tertiary rehabilitation center. METHODS:Adult participants with thoracic or lumbar SCI admitted within 6 months of injury between 2017 and 2025 were included. ASMI was measured at admission using bioelectrical impedance analysis. The primary outcome was MCID-defined improvement in lower extremity motor score (LEMS) during inpatient rehabilitation. Logistic regression and receiver operating characteristic analyses were performed. Subgroup and interaction analyses were conducted. RESULTS:A total of 204 patients were analyzed, of whom 111 (54.4%) achieved MCID-defined recovery. Higher ASMI was independently associated with MCID achievement (adjusted OR 1.52, 95% CI 1.04-2.27; p = 0.035). The multivariable model showed good discrimination (AUC 0.82), whereas ASMI alone had limited performance (AUC 0.59). Sex-specific ASMI thresholds were identified (6.97 kg/m² in males and 5.85 kg/m² in females), with higher discrimination in females. Patients above these thresholds had greater LEMS improvement and higher functional scores at discharge. Significant interactions were observed for sex and injury completeness. CONCLUSIONS:Higher ASMI at admission is associated with greater likelihood of clinically meaningful motor recovery in paraplegic SCI. ASMI may serve as a practical adjunct marker for outcome stratification, and the sex-specific thresholds may help contextualize muscle mass status in relation to motor recovery after paraplegic SCI.
STUDY DESIGN:Methodological cross-sectional validation study with external validation. OBJECTIVES:To develop and externally validate the Infinity Test, a 3-min all-out field protocol performed in the participant's own wheelchair with enforced synchronous propulsion, designed to estimate peak oxygen uptake (VO₂peak) in manual wheelchair users with chronic paraplegia. SETTING:Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute École Bruxelles-Brabant (HE2B), Brussels, Belgium. METHODS:Seventeen manual wheelchair users with chronic paraplegia completed both the Infinity Test and a laboratory arm-crank graded exercise test in counterbalanced order (development cohort). An independent cohort of 11 participants completed the Infinity Test only (external validation cohort). Breath-by-breath VO₂ was measured using a validated portable metabolimeter. Laps·min-1 were derived from manual lap counting using standardized rounding rules and converted to predicted VO₂peak via a linear no-intercept model. Agreement with laboratory VO₂peakErgo was assessed using ICC, Bland-Altman analysis, Passing-Bablok regression, and ordinary least-products regression. Internal validity was evaluated using leave-one-out cross-validation; external validity via correlation and mean absolute error (MAE). RESULTS:Infinity Test VO₂peak∞ did not differ from laboratory VO₂peakErgo (mean bias + 25 mL·min-1, 95% CI-360 to + 410; p = 0.89; ICC = 0.89, 95% CI 0.73-0.96). No fixed or proportional bias was detected. The no-intercept equation (VO₂peak∞ = 461 × laps·min-1) explained 61% of variance in the development cohort (SEE = 517 mL·min-1). External validation showed R² = 0.70 and MAE = 322 mL·min-1 (14.8% of the mean). The protocol was well tolerated and completed in < 5 min including setup. CONCLUSION:The Infinity Test provides a feasible and ecologically valid field protocol for estimating VO₂peak in individuals with paraplegia. Its combination of predictive accuracy, operational simplicity, and use of personal wheelchairs, together with an open-source digital toolkit (interactive nomogram and automated clinical reporting), may support its integration into rehabilitation, high-performance, and community-based practice.
