Mobility profile of chronic stroke classified as Functional Ambulation Category level 4: a cross-sectional study

Ⅰ. Introduction

Stroke remains a leading cause of long-term disability worldwide, leaving many survivors with persistent motor impairments (Feigin et al., 2021). Because mobility underpins independence, gait restoration is a central focus of rehabilitation after stroke (Winstein et al., 2016). Community ambulation usually refers to independent walking outside the home in everyday public environments, such as neighbourhood streets or shops (Lord et al., 2004). By roughly six months post-stroke, many individuals walk independently on level surfaces (Smith et al., 2017). However, their walking speed often remains below thresholds that are considered necessary for full community ambulation (van de Port et al., 2008). Comfortable overground gait speed measured over a middle 10 m walkway segment is widely used to classify household, limited community, and community ambulators, and speeds of about 0.8 m/s or higher are typically interpreted as compatible with community-level walking (Bowden et al., 2008). Even among people who no longer need hands-on assistance, reduced balance confidence and fear of falling can limit outdoor walking and reduce participation in daily activities (Schmid et al., 2012).

Functional Ambulation Category (FAC) is a clinical measure used to classify ambulation ability after stroke based on the amount of physical support required from another person (Mehrholz et al., 2007). In this scale, FAC levels 2 and 3 typically describe individuals who still need continuous or intermittent manual assistance, whereas FAC level 5 indicates independent walking in all environments, including stairs and uneven surfaces (Mehrholz et al., 2007). FAC level 4 indicates that a person can ambulate independently on level surfaces but still requires supervision or occasional assistance for stairs, inclines, or uneven terrain (Yoo & Lim, 2022). Individuals at FAC level 4 therefore represent a transitional subgroup of ambulatory chronic stroke survivors who are beyond strictly household ambulation yet may not achieve fully independent community ambulation (van de Port et al., 2008). Clarifying the gait speed, balance performance, and balance confidence profile of this specific subgroup can help identify residual limitations and guide future studies that compare FAC level 4 with lower (FAC 2-3) and higher (FAC 5) ambulation levels. In this study, we interpreted outcomes within two domains: physical capacity in gait and balance, and self-perceived balance confidence. Physical capacity was characterised by overground 10-m gait speed, instrumented treadmill spatiotemporal parameters, and force-platform and clinical balance measures, with spatiotemporal parameters referring to step length, stride length, cadence, and single-limb support time that describe the temporal and spatial organisation of walking (Olney & Richards, 1996). Balance confidence, defined as a person’s perceived ability to maintain stability during everyday tasks, was assessed with the Activities-specific Balance Confidence scale, which has established reliability and validity in people with stroke (Powell & Myers, 1995). Therefore, the purpose of this study was to comprehensively assess gait characteristics (speed and spatiotemporal parameters), balance (static, dynamic, and functional), and balance confidence in chronic stroke survivors with FAC level 4 ambulation. We hypothesised that, despite their independent level-surface walking ability, these individuals would exhibit gait speed limitations, residual balance impairments, and reduced balance confidence relative to their objective capacity.

Ⅱ. Methods

Ⅲ. Results

1. Participants

Forty ambulatory adults with chronic stroke at FAC level 4 completed the standardized session (n=40); 57.5% were male, mean age 57.18 ± 8.62 years, height 165.78 ± 7.13 cm, weight 65.27 ± 9.64 kg, and time since stroke 39.72 ± 9.18 months; Mini-Mental State Examination–Korean version (MMSE-K) 27.83 ± 1.87. Stroke type was infarction 55.0% and hemorrhage 45.0%; affected side right 55.0%, left 45.0%. See <Table 1> for full summaries.

Table 1.

The general characteristics of the subjects(N = 40)

2. Balance and balance confidence

In instrumented quiet standing, COP sway velocity was 2.19 ± 0.77 cm/s (95% CI, 1.94-2.43), and LOS area 100.62 ± 15.73 cm² (95% CI, 95.59-105.65). On clinical testing, BBS was 47.40 ± 3.76 (95% CI, 46.20-48.60) and TUG 13.57 ± 2.88 s (95% CI, 12.65-14.49). Balance confidence (ABC) averaged 66.36 ± 14.27% (95% CI, 61.80-70.92). Details are provided in <Table 2>.

Table 2.

Balance and gait outcomes (FAC level 4)

Ⅳ. Discussion

This study profiled gait, balance, and balance confidence in independently ambulatory chronic stroke survivors (FAC level 4). Gait speed was a particularly informative mobility measure. Walking speed is strongly linked to functional status and health in older adults (Middleton et al., 2015; Veronese et al., 2018). In stroke, gait velocity often categorizes ambulation ability; for instance, speeds ≥0.8 m/s are typically required for community-level walking. In this cohort, mean comfortable overground speed was 0.74 m/s, approaching the commonly cited 0.80 m/s threshold for community ambulation. However, this was only about 60% of age-matched healthy speed (Murtagh et al., 2021), underscoring a persistent mobility deficit despite independent walking ability. Even among FAC 4 independent walkers, the cohort’s average speed was lower than that typically observed in healthy peers. This finding highlights the need to improve walking speed in rehabilitation.

Consistent with hemiparetic gait patterns, participants had shorter strides, lower cadence, and marked asymmetry in step length and weight-bearing (Chen et al., 2005; Olney & Richards, 1996). The paretic limb’s support phase was notably brief, reflecting impaired weight transfer to the affected side (Wang et al., 2020). These spatiotemporal abnormalities stem from stroke-related muscle weakness and motor control deficits that limit forward propulsion and stepping speed. Importantly, gait asymmetry was associated with increased energy cost and higher fall risk: stroke survivors with more pronounced step-length asymmetry expend more energy and are more prone to balance loss (Little et al., 2020). Thus, even in FAC4 ambulators, residual gait deficits (slowness and asymmetry) are prevalent and clinically relevant. Improving gait speed and symmetry remains a key goal, as faster, more symmetric walking is linked to better community mobility and quality of life after stroke (Fulk et al., 2017).

Balance capacity in this cohort was generally high. The mean Berg Balance Scale (BBS) score was 47/56, generally consistent with low objective fall risk at the group level. Most individuals scored above 45, and any ceiling effect if present appeared limited at the group level. The Timed Up and Go (TUG) time averaged in the low-to-mid teens, suggesting only mild slowing relative to typical values reported in older adults. TUG performance was consistent with overall balance and walking status; no correlation analyses were prespecified. Overall, the balance and mobility outcomes suggest only mild residual impairment: patients could stand and walk independently with reasonably good balance, yet remained somewhat slower and less stable during dynamic tasks than healthy individuals.

A notable discordance was observed between physical balance capacity and self-perceived balance confidence. Despite high BBS scores, balance confidence was moderate on average (mean ABC 66%), suggesting that perceived steadiness may lag behind objective capacity in some individuals. 65% of the cohort had ABC <70% (Abou et al., 2021), reflecting the high incidence of falls post-stroke (Simpson et al., 2011). Additionally, some individuals reported low confidence, indicating perceived risk even during routine tasks and a persistent sense of vulnerability. Such low self-efficacy is associated with poorer physical function and perceived health status after stroke, highlighting its clinical importance beyond objective balance performance (Salbach et al., 2006). Although we did not collect detailed data on fall history, mood, or environmental barriers in this cohort, balance self-efficacy has also been identified as an independent predictor of satisfaction with community reintegration in older adults with chronic stroke, suggesting that unmeasured psychological and contextual factors may contribute to the discordance observed here (Pang et al., 2007). Confidence and objective balance measures represent different constructs, and no correlation analyses were prespecified or performed in this study. Clinically, balance confidence should therefore be considered alongside rather than as a proxy for measured capacity. In the broader literature, individuals with a fall history often report lower balance confidence despite comparable clinical balance scores, consistent with reports linking balance self-efficacy to fall history (Tamis et al., 2024). Psychological factors like fear of falling can persist long after stroke and do not necessarily mirror actual balance capacity. Addressing this confidence gap is crucial, since fear itself can become a barrier to mobility.

These results emphasize the need to target both gait mechanics and psychological confidence. Rehabilitation for chronic stroke should purposefully address both movement mechanics and confidence. In this cohort, objective balance and gait performance were generally good, while balance confidence was only moderate highlighting the practical need to pair task-specific gait/balance practice with strategies that reduce fear of falling and support self-efficacy (e.g., graded exposure, progressive task difficulty, brief cognitive reframing within sessions). Notably, adding cognitive-behavioral components to task-oriented balance training has been reported to reduce fear of falling compared with training alone (Liu et al., 2019). Embedding such elements can help translate laboratory performance into safer, more willing participation in community walking.

Several limitations should be considered when interpreting these findings. First, this was a single-center observational cross-sectional study with a modest sample size, and all analyses were descriptive; the results therefore cannot support causal inference or strong prognostic conclusions and may not generalize beyond similar rehabilitation settings. In addition, we did not conduct correlation analyses between gait, balance, and balance confidence measures, which limits inferences about their interrelationships. Second, all data were collected within a single testing session using a fixed assessment order, and we did not evaluate test–retest reliability, so potential fatigue, learning effects, or order effects may have influenced performance, particularly during the later treadmill condition. Third, balance and gait were assessed under controlled laboratory conditions using a force platform and an instrumented treadmill in a quiet indoor environment, which may not fully reflect the demands of outdoor walking or busy community settings. Fourth, we did not maintain a screening log and thus could not characterize individuals who were ineligible or who declined participation, so some degree of self-selection bias is likely. Fifth, we did not collect measures of walking endurance or participation, such as the 6-minute walk test, Reintegration to Normal Living Index, or Community Integration Measure, and we were therefore unable to examine how gait capacity and balance confidence relate to broader aspects of community ambulation and participation. Within these limitations, the present results describe gait speed, spatiotemporal gait characteristics, standing balance, and balance confidence in a clearly defined FAC level 4 cohort and may assist clinicians and researchers when planning interventions and future trials for this transitional subgroup of ambulatory adults with chronic stroke.

Ⅴ. Conclusion

Among ambulatory adults with chronic stroke (FAC level 4), mobility was generally good: overground gait speed averaged 0.74 m/s (close to the commonly cited 0.80 m/s community ambulation threshold), and both clinical and instrumented balance measures were high. Nevertheless, balance confidence remained only moderate, suggesting persistent fear of falling and perceived instability in everyday situations and indicating that gait speed is best viewed as a practical summary index of activity-level walking capacity rather than a direct measure of community participation. Rehabilitation should therefore combine gait and balance training with confidence-building strategies (e.g., graded exposure, progressively more challenging community-relevant tasks, brief cognitive–behavioural components), and longitudinal studies are needed to clarify how such combined approaches affect participation outcomes.

References

• Abou L, Alluri A, Fliflet A, et al. Effectiveness of physical therapy interventions in reducing fear of falling among individuals with neurologic diseases: a systematic review and meta-analysis. Arch Phys Med Rehabil 2021;102(1):132-154. [https://doi.org/10.1016/j.apmr.2020.06.025]
• Avelino PR, Menezes KK, Nascimento LR, et al. Walking speed best explains perceived locomotion ability in ambulatory people with chronic stroke, assessed by the ABILOCO questionnaire. Braz J Phys Ther 2019;23(5):412-418. [https://doi.org/10.1016/j.bjpt.2018.12.005]
• Bohannon RW, Glenney SS. Minimal clinically important difference for change in comfortable gait speed of adults with pathology: a systematic review. J Eval Clin Pract 2014;20(4):295-300. [https://doi.org/10.1111/jep.12158]
• Bowden MG, Balasubramanian CK, Behrman AL, et al. Validation of a speed-based classification system using quantitative measures of walking performance poststroke. Neurorehabil Neural Repair 2008;22(6):672-675. [https://doi.org/10.1177/1545968308318837]
• Bruyneel AV, Mesure S, Reinmann A, et al. Validity and reliability of center of pressure measures to quantify trunk control ability in individuals after stroke in subacute phase during unstable sitting test. Heliyon 2022;8(10):e10891. [https://doi.org/10.1016/j.heliyon.2022.e10891]
• Chen G, Patten C, Kothari DH, et al. Gait differences between individuals with post-stroke hemiparesis and nondisabled controls at matched speeds. Gait Posture 2005;22(1):51-56. [https://doi.org/10.1016/j.gaitpost.2004.06.009]
• Cheng DKY, Dagenais M, Alsbury-Nealy K, et al. Distance-limited walk tests post-stroke: a systematic review of measurement properties. NeuroRehabilitation 2021;48(4):413-439. [https://doi.org/10.3233/NRE-210026]
• Encarnación-Martínez A, Pérez-Soriano P, Sanchis-Sanchis R, et al. Validity and reliability of an instrumented treadmill with an accelerometry system for assessment of spatio-temporal parameters and impact transmission. Sensors (Basel) 2021;21(5):1758. [https://doi.org/10.3390/s21051758]
• Feigin VL, Stark BA, Johnson CO, et al. Global, regional, and national burden of stroke and its risk factors, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019. Lancet Neurol 2021;20(10):795-820. [https://doi.org/10.1016/S1474-4422(21)00252-0]
• Fulk GD, He Y, Boyne P, et al. Predicting home and community walking activity poststroke. Stroke 2017;48(2):406-411. [https://doi.org/10.1161/STROKEAHA.116.015309]
• Lininger MR, Leahy TE, Haug EC, et al. Test-retest reliability of the limits of stability test performed by young adults using NeuroCom VSR Sport. Int J Sports Phys Ther 2018;13(5):800-807. [https://doi.org/10.26603/ijspt20180800]
• Little VL, Perry LA, Mercado MW, et al. Gait asymmetry pattern following stroke determines acute response to locomotor task. Gait Posture 2020;77:300-307. [https://doi.org/10.1016/j.gaitpost.2020.02.016]
• Liu TW, Ng GY, Chung RC, et al. Decreasing fear of falling in chronic stroke survivors through cognitive behavior therapy and task-oriented training. Stroke 2019;50(1):148-154. [https://doi.org/10.1161/STROKEAHA.118.022406]
• Lord SE, McPherson K, McNaughton HK, et al. Community ambulation after stroke: how important and obtainable is it and what measures appear predictive? Arch Phys Med Rehabil 2004;85(2):234-239. [https://doi.org/10.1016/j.apmr.2003.05.002]
• Mehrholz J, Wagner K, Rutte K, et al. Predictive validity and responsiveness of the Functional Ambulation Category in hemiparetic patients after stroke. Arch Phys Med Rehabil 2007;88(10):1314-1319. [https://doi.org/10.1016/j.apmr.2007.06.764]
• Middleton A, Fritz SL, Lusardi M. Walking speed: the functional vital sign. J Aging Phys Act 2015;23(2):314-322. [https://doi.org/10.1123/japa.2013-0236]
• Miyata K, Tamura S, Kobayashi S, et al. Berg Balance Scale is a valid measure for plan interventions and for assessing changes in postural balance in patients with stroke. J Rehabil Med 2022;54:jrm00359. [https://doi.org/10.2340/jrm.v54.4443]
• Murtagh EM, Mair JL, Aguiar E, et al. Outdoor walking speeds of apparently healthy adults: a systematic review and meta-analysis. Sports Med 2021;51(1):125-141. [https://doi.org/10.1007/s40279-020-01351-3]
• Olney SJ, Richards C. Hemiparetic gait following stroke. Part I: characteristics. Gait Posture 1996;4(2):136-148. [https://doi.org/10.1016/0966-6362(96)01063-6]
• Pang MYC, Eng JJ, Miller WC. Determinants of satisfaction with community reintegration in older adults with chronic stroke: role of balance self-efficacy. Phys Ther 2007;87(3):282-291. [https://doi.org/10.2522/ptj.20060142]
• Powell LE, Myers AM. The Activities-specific Balance Confidence (ABC) scale. J Gerontol A Biol Sci Med Sci 1995;50(1):M28-M34. [https://doi.org/10.1093/gerona/50A.1.M28]
• Salbach NM, Mayo NE, Robichaud-Ekstrand S, et al. Balance self-efficacy and its relevance to physical function and perceived health status after stroke. Arch Phys Med Rehabil 2006;87(3):364-370. [https://doi.org/10.1016/j.apmr.2005.11.017]
• Schmid AA, Van Puymbroeck M, Altenburger PA, et al. Balance and balance self-efficacy are associated with activity and participation after stroke: a cross-sectional study in people with chronic stroke. Arch Phys Med Rehabil 2012;93(6):1101-1107. [https://doi.org/10.1016/j.apmr.2012.01.020]
• Seamon BA, Kautz SA, Velozo CA. Rasch analysis of the Activities-specific Balance Confidence scale in individuals poststroke. Arch Rehabil Res Clin Transl 2019;1(3-4):100028.
• Simpson LA, Miller WC, Eng JJ. Effect of stroke on fall rate, location and predictors: a prospective comparison of older adults with and without stroke. PLoS One 2011;6(4):e19431. [https://doi.org/10.1371/journal.pone.0019431]
• Smith MC, Barber PA, Stinear CM. The TWIST algorithm predicts time to walking independently after stroke. Neurorehabil Neural Repair 2017;31(10-11):955-964.
• Tamis WP, Winser SJ, Wayne L, et al. Association between fear of falling and falls following acute and chronic stroke: a systematic review with meta-analysis. J Rehabil Med 2024;56:jrm18650. [https://doi.org/10.2340/jrm.v56.18650]
• Van Alsenoy K, Thomson A, Burnett A. Reliability and validity of the Zebris FDM-THQ instrumented treadmill during running trials. Sports Biomech 2019;18(5):501-514. [https://doi.org/10.1080/14763141.2018.1452966]
• van de Port IG, Kwakkel G, Lindeman E. Community ambulation in patients with chronic stroke: how is it related to gait speed? J Rehabil Med 2008;40(1):23-27.
• Veronese N, Stubbs B, Volpato S, et al. Association between gait speed with mortality, cardiovascular disease and cancer: a systematic review and meta-analysis of prospective cohort studies. J Am Med Dir Assoc 2018;19(11):981-988.e7. [https://doi.org/10.1016/j.jamda.2018.06.007]
• Wang Y, Mukaino M, Ohtsuka K, et al. Gait characteristics of post-stroke hemiparetic patients with different walking speeds. Int J Rehabil Res 2020;43(1):69-75. [https://doi.org/10.1097/MRR.0000000000000391]
• Winstein CJ, Stein J, Arena R, et al. Guidelines for adult stroke rehabilitation and recovery: a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke 2016;47(6):e98-e169. [https://doi.org/10.1161/STR.0000000000000098]
• Yoo YJ, Lim SH. Assessment of lower limb motor function, ambulation, and balance after stroke. Brain Neurorehabil 2022;15(2):1-8. [https://doi.org/10.12786/bn.2022.15.e17]