Introduction
Trench foot, also referred to as immersion foot, is a nonfreezing cold injury resulting from prolonged exposure of the feet to cold, wet environments.Reference Zafren, Danzyl and Grayzel 1 Individuals exposed to floods, heavy rainfall, or post-earthquake conditions in cold and wet environments are particularly at risk of developing trench foot. Prevention is critical, particularly in cold and wet settings, where regularly changing wet socks and maintaining dry feet are essential.Reference Ungley, Channell and Richards 2 Military personnel are typically advised to carry two pairs of socks, including a spare.Reference MacPherson, Horrocks and Beveridge 3 However, in disaster environments, obtaining multiple pairs of socks in varying sizes is challenging, and wet socks tend to dry slowly while losing their insulating capacity. In such situations, footwraps may serve as a practical alternative to socks. This technique involves wrapping rectangular or square pieces of cloth around the feet before putting on footwear.Reference Forty, Hook and Cornish 4 Although footwraps were eventually replaced by socks following mass production, they continued to be used in Eastern European militaries until the early 21st century.Reference Socks 5 Footwraps are cost-effective, easy to clean, adaptable to different foot sizes and shapes, and can still provide coverage even when the cloth has holes by wrapping over them. Moreover, cloth generally dries faster than socks and can be easily dried near a heat source. These advantages suggest that footwraps are feasible substitutes for socks in resource-limited post-disaster settings.Reference Suito, Yanagida and Ohtsubo 6
This study aimed to examine the learning process for the footwrap technique across different age groups and evaluate its practical applicability as a substitute for socks.
Methods
Participant Selection and Grouping
Skill acquisition may differ between healthcare professionals and laypersons. Therefore, volunteers from the general population with no prior experience in using footwraps were recruited. Participants were stratified into four age groups (15-29, 30-49, 50-69, and ≥70 years) based on previous findings showing age-related differences in skill acquisition,Reference Voelcker-Rehage and Willimczik 7 particularly the superior learning ability observed in individuals aged 15-29 years.
Cloth for Footwraps
For the footwraps, a piece of cloth measuring 40 × 70 cm was cut from a triangular bandage (105 × 105 × 150 cm, cotton; SUZURAN MEDICAL INC., Nagoya, Japan). This material was selected for several reasons. First, traditional Russian military practice used cotton cloth during summer and flannel during winter to improve insulation.Reference Hartston 8 Second, triangular bandages are readily obtainable and serve as a standardized material for pre-disaster training, thereby facilitating consistent practice and improving study reproducibility. Additionally, cotton cloth can be obtained from used clothing, shirts, or bed sheets during disasters. Third, conventional footwraps typically use either 40-cm square cloths or 40 × 75 cm rectangular clothsReference Socks 5; therefore, the selected dimensions (40 × 70 cm) represent the largest size obtainable from a single triangular bandage. Finally, cotton cloth has multiple applications in disaster settings, supporting hygiene and other purposes beyond footwrapping.
Footwrap Instruction, Assessment, and Application Procedures
A standardized footwrap technique was used throughout the study (Figure 1). Participants stood on the floor, selected one foot, removed the sock, and placed the bare foot on a cloth positioned on a 40-cm-high table. The first author provided direct verbal instruction and demonstrated the wrapping procedure on the participant’s foot two or three times without using visual aids or infographics. Following the demonstrations, participants independently performed the footwrap procedure 10 times. During these trials, footwrap quality was assessed using three criteria: “minimal wrinkling” to reduce blister formation, “adequate foot coverage” to minimize injury risk, and “optimal tightness” to prevent circulatory impairment or loosening. Each criterion was rated on a 3-point scale, and feedback was provided after each trial. Additionally, the following performance metrics were recorded: the number of trials required to achieve proficiency (for each criterion and overall); duration of each trial; and total time from instruction to the completion of the 10th trial, including any rest periods. Timing began when the foot was placed on the cloth (Figure 1a) and ended when the edge of the cloth was tucked in and secured (Figure 1o). All assessments were performed by the first author.
Method of footwrapping. (a) Overall view at the beginning (shoe size: 27.0 cm; cloth size: 40 × 70 cm). (b) Position the foot on the hypotenuse of an isosceles right triangle as depicted in the figure (orange solid line). Ensure equal distance from the toe and heel to the cloth edges. Adjust the foot’s position such that the portion marked by the blue circle fits under the sole, as illustrated in Fig. 1d. (c) Cover the toes. (d) Elevate the heel. With the contralateral hand, guide the cloth edge under the plantar surface and cover the foot dorsum. If the edge does not go under, adjust the position of the foot and try again. (e) While elevating the heel and holding the cloth placed beneath the sole, use the ipsilateral hand to pull the cloth, removing plantar wrinkles and ensuring that the cloth conforms closely to the foot. (f) Pull the cloth upward to cover the Achilles tendon area. (g) Grasp both ends of the cloth with both hands, ensuring that the ipsilateral hand holds the rear edge of the cloth. (h) Twist the cloth by extending the ipsilateral hand forward while pulling the contralateral hand backward. (i) Hold both edges of the cloth with the contralateral hand. With the ipsilateral hand, lift and hold the portion of the cloth that was previously pulled upward to cover the Achilles tendon area (Figure f). (j) Wrap the cloth around the distal lower leg over the portion covering the Achilles tendon area. (k) Position the wrap one to two finger-widths proximal to the ankle bone to minimize displacement from ankle movement and prevent loosening. For smaller feet, wrap excess cloth around the distal leg before tucking to secure fixation. (l) Loosen the cloth at the distal lower leg and insert the cloth end between the skin and overlying cloth layers. If insertion is difficult due to tight wrapping, adjust tension. To increase friction between cloth layers and prevent unraveling, insert the cloth end along the wrapping direction around the lower leg rather than distally toward the foot. (m) Pull the loosened cloth in the tucking direction to ensure adequate tension. (n) Advance the cloth end further along the wrapping direction to achieve firm fixation. Repeat steps (m) and (n) once or twice until the fixation is secure. (o) Fixation of the cloth has been completed.
Figure 1. Long description
Figure 1 presents a 15-panel, step-by-step demonstration of the footwrap technique using a 40 × 70 cm cloth cut from a cotton triangular bandage. The panels are arranged in three rows of five. Panel (a) shows the initial positioning of the foot and cloth. In panel (b), the cloth is positioned diagonally across the foot, with the toe and heel positioned equidistant from the edges of the cloth. Panel (c) shows the anterior corner of the cloth placed over the toes. In panels (d–e), the heel is lifted while the cloth edge is passed beneath the sole and the cloth is pulled to conform closely to the foot. Panel (f) shows the cloth being pulled upward to cover the Achilles tendon area. Panels (g–i) show the two corners of the cloth being grasped with both hands, followed by twisting the cloth and wrapping it around the distal lower leg. In panels (j–k), the cloth wrapped around the distal lower leg is positioned one to two finger-widths proximal to the ankle bone. Panels (l–n) show the cloth end being tucked between the skin and the overlying cloth layers, followed by advancing the wrapped cloth in the direction of wrapping and further tucking the cloth end between the layers. This process is repeated to secure the fixation. Panel (o) shows the completed footwrap.
After the 10th trial, participants wore shoes with one foot wrapped and the other unwrapped after sock removal. They wore the shoes for 30 min, including at least 10 min of walking, after which they completed a questionnaire. The 30-min duration was selected to assess early mechanical irritation while minimizing the risk of overt skin injury, particularly under unwrapped conditions. All experiments were conducted indoors at 25°C, with each participant individually completing the full protocol.
Content and Purpose of the Questionnaire
The questionnaire assessed the feasibility of footwraps as substitutes for socks. Unwrapped and footwrap conditions were compared across key functional characteristics commonly associated with socks, namely, friction-related pain reduction, shoe fit, moisture absorption, heat retention, and overall comfortReference Socks 5 , Reference Dai, Li and Zhang 9 (each assessed using a 5-point scale). Footwear comfort was also evaluated separately under each condition using a 5-point scale, with socks serving as the reference condition. Footwrap stability and internal shoe tightness during walking, as well as acceptability for shelter use, were evaluated using a 2-point scale. Participants who reported loosening during walking were interviewed by the first author to identify potential contributing factors.
Statistical Analysis
Qualitative evaluations of the footwrap technique; the time required for the 1st, 5th, and 10th trials; and the total completion time were each analyzed and compared across age groups using the Kruskal-Wallis test followed by Bonferroni-corrected post hoc analysis.
Subjective ratings obtained from the 5-point scales were analyzed using the one-sample Wilcoxon signed-rank test to determine whether score distributions significantly differed from the reference value of 3. For the five key functional parameters associated with socks, a score of 3 indicated equivalence between unwrapped and footwrap conditions. For footwear comfort, a score of 3 represented equivalence to the reference sock condition, and the unwrapped and footwrap conditions were each compared with this reference value. Statistical analyses were performed using EZR (Jichi Medical University, Saitama, Japan), a graphical interface for R (The R Foundation for Statistical Computing, Vienna, Austria); P values <0.05 denoted statistically significant differences.
Results
This study included 100 participants (50 men and 50 women), with 25 participants in each age group (Table 1).
Details and results of each evaluation criterion
Table 1. Long description
The table is organized into columns that present the description and assessment criteria; results for all participants (n = 100); overall P values; results for four age groups (A: 15–29, B: 30–49, C: 50–69, and D: ≥70 years; n = 25 each); and P values for comparisons among age groups.
Key data sections include:
* Demographics: The study included 100 participants, with an equal number of men and women. The mean age was 49.7 ± 20.3 years. The median shoe size was 26.5 cm for men and 23.5 cm for women.
* Qualitative evaluation of the footwrap technique: The median number of trials required to achieve minimal wrinkling was 1 in all age groups except for those aged ≥70 years (2 trials), while the median for adequate foot coverage was 1 in all age groups. For appropriate tightness, the median was lowest in participants aged 30–49 years (2 trials) and highest in those aged ≥70 years (9 trials).
* Time required: Times were recorded for the 1st, 5th, and 10th trials, as well as the total time required from instruction to the completion of the 10th trial. Participants aged 30–49 years had the shortest median times for the 1st, 5th, and 10th trials and the shortest total completion time, whereas those aged ≥70 years had the longest total completion time.
* Sock -substitution performance : While wearing shoes, the footwrap condition was rated significantly more favorably than the unwrapped condition for shoe fit, moisture absorption, heat retention, and overall comfort (P < 0.001). No significant difference was observed for friction-related pain reduction.
* Footwear comfort compared with the sock reference: The unwrapped condition was rated significantly less comfortable than the sock reference, whereas no significant difference was observed between the footwrap condition and the sock reference.
* Practical use and stability: Footwrap loosening within 30 min occurred in 17 participants (17%), consistently at the distal lower-leg fixation site. 98% reported no shoe tightness, and 100% reported willingness to use footwraps in shelters if socks were unavailable.
SD: Standard deviation. Q1: first quartile (25th percentile); Q3: third quartile (75th percentile).
k Kruskal-Wallis test; wone-sample Wilcoxon signed-rank test.
By the 10th trial, all participants met the minimum proficiency criteria for the footwrap technique. However, repeated trials revealed several technical challenges. In the qualitative assessment, wrinkles were commonly observed on the plantar surface, although no significant age-related differences were identified in the number of trials required to achieve proficiency. Inadequate coverage frequently occurred around the Achilles tendon, and insufficient extension of the plantar portion of the cloth often resulted in incomplete coverage of the fifth toe. Significant age-related differences were observed in the number of trials required to achieve adequate foot coverage (P = 0.033). Regarding tightening errors, footwraps were more often applied too loosely than too tightly, particularly at the distal lower leg fixation site. Participants aged ≥70 years required significantly more trials to achieve appropriate tightening than those aged 15-29 years (P = 0.005) and 30-49 years (P < 0.001).
In addition to technical performance, age-related differences were observed in body positioning during footwrapping. Due to back pain, balance limitations, or table height, one participant aged 50-69 years and two participants aged ≥70 years performed footwrapping while standing with the target foot placed on a 30-cm-high table. Furthermore, one participant aged 50-69 years and 17 participants aged ≥70 years performed footwrapping while seated on a 40-cm-high chair with the target foot placed on a 30-cm-high table.
Participants aged 30-49 years showed the shortest median times for the 1st, 5th, and 10th trials, as well as the shortest total completion time. The longest total completion time was observed among participants aged ≥70 years.
Regarding performance as a sock substitute while wearing shoes, the footwrap condition received significantly higher ratings than the unwrapped condition for shoe fit, moisture absorption, heat retention, and overall comfort (P < 0.001), whereas no significant difference was observed for friction-related pain reduction. For footwear comfort, the unwrapped condition was rated significantly less comfortable than the sock reference across all age groups, whereas no significant difference was observed between the footwrap condition and the sock reference.
Footwrap loosening within 30 min occurred in 17 participants, consistently at the distal lower leg fixation site. Presumed contributing factors included putting on shoes (n = 1), brisk walking or light jogging (n = 2), climbing up and down more than four flights of stairs (n = 2), wearing oversized shoes (n = 2), insufficient cloth length (n = 3), and normal walking (n = 7). Among the 100 participants, 98 reported no shoe tightness while using footwraps, and all indicated a willingness to use footwraps in shelters if socks were unavailable.
Discussion
This study examined the use of footwraps as an alternative to socks in disaster and resource-limited settings. Their feasibility is supported by the use of readily available cloth materials, minimal space and physical requirements, and their historical application in military settings.
Among the three evaluation criteria for the footwrap technique—minimal wrinkling, adequate foot coverage, and optimal tightness—minimal wrinkling and adequate foot coverage were generally achieved after a median of one to two trials, regardless of age, whereas achieving optimal tightness at the distal lower leg fixation site required more trials in each age group and represented the primary obstacle to acquisition. During the subsequent 30-min wearing period, 17% of participants experienced loosening, with all cases occurring at the distal lower leg. This distribution was likely attributable to the difficulty in achieving secure fixation at this site, in addition to increased ankle movement and mechanical stress during activities such as stair descent or brisk walking.
Importantly, even a 17% loosening rate within 30 min represents a clinically meaningful safety concern, as loosening during evaluation or prolonged ambulation may increase the risk of tripping, falls, or secondary injury. These findings emphasize the importance of incorporating re-tightening instructions into disaster preparedness training, with specific guidance on periodic inspection and adjustment of wrap tension. In addition, alternative fixation methods focused on distal lower leg stability may simplify the technique, facilitate skill acquisition, and reduce the risk of loosening. Future research can investigate the effects of a simple fixation method using duct tape to secure the end of the cloth, instead of tucking it under the overlying layers, on skill acquisition and footwrap stability during prolonged use. However, this concept was not evaluated in the present study and therefore requires formal investigation before any conclusions can be drawn.
Participants aged ≥70 years required significantly more trials and longer total completion times to achieve proficiency than those aged 30-49 years, indicating slower skill acquisition. Across all age groups, the time required for each trial did not consistently decline with repetition. Initial trials were longer because of unfamiliarity, whereas later trials reflected greater attention to technique refinement. Footwrapping also posed notable ergonomic challenges for older adults, many of whom required seated positioning or modified table heights. Thus, balance, flexibility, and lower-extremity mobility are crucial for effective skill acquisition, suggesting that age-related differences reflect both cognitive and physical demands.
A 40 × 70-cm cloth can be used to wrap feet up to a shoe size of 28.0 cm, although it appears more suitable for sizes ≤27.0 cm. Participants with larger feet, edema, or greater distal lower leg circumference had less remaining cloth available at the fixation site, which occasionally resulted in insufficient fixation. In contrast, a 40 × 80-cm rectangular cloth from a triangular bandage, despite lacking a corner, provided sufficient length to secure the lower leg and improved fixation even among participants with 28-cm feet. Notably, 98% of participants reported no shoe tightness while using footwraps, indicating appropriate cloth thickness. This characteristic is particularly valuable because maintaining circulation and avoiding excessive compression are essential for reducing the risk of trench foot.3
Footwraps effectively reproduced key functions of socks, including improved shoe fit, moisture absorption, heat retention, and overall comfort. Friction-related pain reduction was the only outcome with no significant difference, potentially because of the short evaluation period. Regarding footwear comfort, the unwrapped condition was significantly less comfortable than the sock reference, whereas no significant difference was observed between the footwrap condition and the sock reference, suggesting that footwraps may be a practical alternative to socks.
All participants expressed a willingness to use footwraps when socks were unavailable in evacuation shelters, indicating high acceptability. These findings support incorporating footwrap instruction into disaster preparedness education and evacuation planning protocols.
Limitations
This study has several limitations. First, this study included only Japanese participants aged ≥15 years; therefore, the findings may not be generalizable to children, to individuals with different educational backgrounds, or to those with disabilities. Second, the study was not conducted under actual disaster conditions or in cold, wet environments. As all experiments were conducted indoors at 25°C, the study evaluated only mechanical proficiency and short-term comfort, and thus did not assess thermal insulation or moisture control, both of which are essential for trench foot prevention. Third, the training was instructor-led rather than self-directed because a hands-on teaching approach was adopted to simulate disaster conditions in which visual instructional materials may be unavailable. Thus, future studies should evaluate the effectiveness of visual aids and independent instructional methods. Fourth, only cotton cloth of a fixed thickness was evaluated; other materials and thicknesses were not examined. Fifth, long-term effectiveness and retention of the footwrap technique were not evaluated. Sixth, all assessments were performed by the first author. As this was an exploratory study, a single evaluator was used to ensure consistent application of the predefined scoring criteria and to minimize inter-rater variability throughout the study. However, this approach may have introduced observer bias because the assessments were not independently or blindly verified. Future studies should incorporate multiple independent or blinded evaluators to improve objectivity and reduce potential bias. Finally, the relatively small sample size limits the generalizability of the findings, emphasizing the need for larger studies involving more diverse populations.
Conclusions
In resource-limited settings, footwraps may serve as a practical alternative to socks. Age-related differences in footwrap skill acquisition underscore the importance of tailored instructional approaches to support effective learning and application across different age groups.
Acknowledgments
The authors are grateful to Professor Akihiro Hirakawa of the Institute of Science Tokyo for his valuable advice on statistical methodology and to all the volunteers who participated in this study.
Author contributions
Study concept and design: MS, TY, KT, NK; Data acquisition: MS; Data analysis: MS; Writing—original draft: MS. All authors read and approved the final manuscript.
Funding statement
No funding was received for this work.
Competing interests
None.
Ethical standards
The Institutional Review Board of Jisenkai, Nagano, Japan, approved this study (approval number: 2025-030) on May 27, 2025. All participants provided written informed consent.
