A Survey Of Deployed Foot Problems In A Desert Environment

ABSTRACT

A casual comment made regarding the amount of “mole skin” being dispensed to airmen to handle blisters, pressure points, and foot pain led to the development of an impromptu voluntary survey in an attempt to quantify the number of personnel with foot care concerns and the spectrum of those problems. With only a small number of sick call visits related to foot and ankle problems, the amount of mole skin being dispensed was surprising. This survey represents the results of a comprehensive evaluation of a base population involved in support of the first 2 months of Operation Iraqi Freedom.

Issue Section:

 Clinical report

INTRODUCTION

During a conversation with medical technicians at an austere desert base in 2002, a casual comment was made regarding the amount of “mole skin” that was being dispensed to airmen to handle blisters, pressure points, and foot pain. Fifteen square feet was being used on a monthly basis for a base population of approximately 1,500 personnel. The amount of mole skin being dispensed came as a shock as only a small number of sick call visits were related to foot and ankle problems. As a result, an impromptu voluntary survey was conducted in an attempt to quantify the number of personnel with foot care concerns and the spectrum of those problems (Table I, columns 1 and 2). A foot care brief was developed for the base to deal proactively with these concerns. In addition, a comprehensive literature search on the problem was done to support recommendations, which resulted in a very limited number of relevant articles.

TABLE I

Foot Care Survey

	Impromptu 405th EMDG, June 19, 2002		Formal 487th EMDG, May 20, 2003
Foot Care Survey	Column 1 (n)	Column 2 (%)	Column 3 (n)	Column 4 (%)
Foot problems before deployment
Yes	17	11.49	15	4.40
No	131	88.51	326	95.60
Advance issue of desert boots
≤2 weeks	97	66.90	181	54.35
> 2 weeks	48	33.10	152	45.65
Time to break in boots
Yes	65	44.83	127	37.35
No	80	55.17	213	62.65
Foot concerns since arrival	87	58.39	84	24.63
Foot pain/aching	32	36.78	25	29.76
Toe pain/aching	32	36.78	15	17.86
Corns	7	8.05	3	3.57
Bunions	4	4.60	3	3.57
Blisters	56	64.37	37	44.05
Calf pain/aching	6	6.90	8	9.52
Skin cracking	22	25.29	17	20.24
Calluses	23	26.44	13	15.48
Itching/burning	14	16.09	17	20.24
Ingrown nails	3	3.45	4	4.76
Longest time in boots
≤12 hours	20	13.16	76	22.35
>12 hours	122	84.72	269	79.12
Swap out socks through shift
Yes	11	7.38	65	19.17
No	138	92.62	274	80.83
Number of respondents	149		341

 

Personnel with blisters have been found to be at a higher risk for subsequent injury, which could potentially interfere with mission execution.¹ Therefore, it seemed reasonable to attempt to quantify the nature and extent of foot problems during a future deployment in 2003 to an austere desert environment. This survey represents the results of a comprehensive evaluation of a base population involved in support of the first 2 months of Operation Iraqi Freedom (Table I, columns 3 and 4).

METHODS/DATA ANALYSIS

The method of data collection was a survey filled out by every active duty Air Force, Air Force Reserve, and Air National Guard member deployed to a base in Southwest Asia during the time period of March to May 2003. Although all members deployed to the base were required to fill out the survey, consent was not required since all data were collected anonymously. A total of 341 surveys were analyzed. The survey captured information regarding foot problems before deployment (yes or no), advance issue of desert boots (≤2 weeks, >2 weeks), whether break-in time was adequate (yes or no), foot concerns since arrival (yes or no), the use of steel-toe boots (yes or no), the longest time spent in boots (≤12 hours, >12hours), whether socks were swapped out (yes or no), and whether adequate foot care information had been provided to the member (yes or no). The categories under “foot concerns since arrival” included the following: foot pain/aching, toe pain/aching, corns, bunions, blisters, calf pain/aching, skin cracking, calluses, itching/burning, and ingrown nails.

Overall incidence rates were calculated. Relative risks, with 95% confidence intervals were used to examine the relationship between foot concerns since arrival in-theater and factors that may have influenced them. Logistic regression (backward selection) was used to determine important statistical associations. Statistical analysis was performed using SAS statistical software (version 9.1.3; SAS Institute, Cary, North Carolina).

RESULTS

Included in this analysis were surveys completed by the base population of 341. Eighty-four members reported foot concerns since their arrival in-theater, for an incidence rate of 24.63 foot concerns per 100 members. Forty-four percent of those who reported concerns reported more than one foot problem. Blisters were the most common reported problem in this group, accounting for 44% of foot concerns since arrival in theater (Table I, columns 1 and 2). This represented 10.9% of the base population.

There were three factors that showed a positive correlation for those members who indicated they had foot concerns since their arrival in-theater. These were: previous problems (relative risk, 2.64; 95% confidence interval, 1.66–4.17), >12 hours in their boots (relative risk, 1.26; 95% confidence interval, 1.13–1.41), and 2 weeks or less of advance issue of their boots (relative risk, 1.71; 95% confidence interval, 1.14–2.57) (Table II). Although not statistically significant, there was an association between foot concerns since arrival in-theater and adequate break-in time, steel-toe boots, swapping out socks, and adequate care instructions.

TABLE II

Association between Foot Concerns Since Arrival In-Theater and Other Factors

Factor	Relative Risk	95% Confidence Intervals	pa
Previous problems	2.64	1.66–4.17	0.001
Time in boots >12 hours	1.26	1.13–1.41	0.001
Advance issue of boots	1.71	1.14–2.57	0.008
≤2 weeks Adequate boot break in time	0.72	0.49–1.00	NS
Steel-toe boots	1.3	0.86–1.97	NS
Swapping out socks	1.34	0.88–2.05	NS
Adequate foot care information	0.85	0.35–2.06	NS

a A significant p value is defined as <0.05. NS, nonsignificant.

 

DISCUSSION

Previous studies have clearly demonstrated the significance of foot morbidity in military populations. Blisters are an important source of morbidity and were associated with a 50% increase in the subsequent risk for other lower extremity injury in a prospective study of Marine recruits during initial physical training.¹While in our survey only 3% of sick call visits involved blisters, 11% of those involved in the survey reported experiencing blisters. In addition, while only 12% of sick call visits were related to foot concerns, 25% of the base population reported they had foot concerns during the deployment. The implication of foot disorders relates to the potential for degraded performance of members and subsequent risk to mission execution. The deployed personnel in this survey showed a rate of blister formation of 5.43 per 100 member months during this deployment as compared to only 2.05 per 100 recruit months in the Marine initial physical training study.¹

One study attempted to evaluate the impact of using antiperspirants, in the form of 20% aluminum zirconium tetrachloridyrox glycine in an emollient base, on blister formation. Their simulation involved marching at 3.1 mph (1.39 m/s) for 200 minutes with a 46-lb pack (21 kg) at a temperature of 84°F (28°C) and 25% relative humidity.²They found no difference in sweat accumulation, hot spots, and blisters (size or number). Concerns with the lack of response in this study relate to: the limited duration in the boots (> 12 hours in the field in our survey), the heat stress (40°C in the field in our deployment), and the specific antiperspirant in combination with an emollient (6–20% aluminum chloride hexahydrate is the current topical standard of care).^2,3 There were no comparative studies available for 15% aluminum chloride aqueous solution (Maxim, over-the-counter; Conrad Healthcare, Inc. Available at http://www.stopsweat.com) or 20% aluminum chloride hexahydrate (Drysol by prescription), but they remain the primary recommendation for the topical treatment of plantar hyperhidrosis.⁴ Tinea pedis can be a considerable additional risk through skin maceration secondary to the occlusive effect of the boot, heat, and perspiration. Although topical antifungals remain a mainstay of treatment, it is important not to forget the benefit of a 1:40 Burow's solution soak and the therapeutic utility and convenience of an application of 1:10,000 potassium permanganate.⁵

Although nothing could be found in the literature on the role of “mole skin,” there is no question that it can be used to effectively reduce pressure points and friction as well as protect boney prominences.

LIMITATIONS

This survey had several limitations reflecting the lack of information on the age, sex, race, and body mass index of the personnel surveyed. There have been concerns that foot pain can be correlated to body mass index.⁶ It has also been suggested that women's higher arch put them at higher risk of problems in traditional combat boots, while older populations will experience a greater incidence of static foot deformities (hallux valgus, hallux rigidus, bunions) predisposing them to secondary foot problems.⁷ Lastly, there was no control population surveyed concurrently at a home base, so it remains unclear as to the exact burden on personnel's feet from a deployed desert environment alone.

CONCLUSIONS

Based on our analysis, anyone with a previous history of foot problems represents the greatest risk while deployed. Addressing this aggressively before deployment could reduce the risk of problems while deployed. General principles for deployed foot care could be provided to troops before deployment and again during their in-processing brief. An example is provided in Table III. Issuing boots to allow sufficient time to break them in properly (>2 weeks) as well as ensuring that they are worn and broken in before deployment should reduce subsequent problems. Predeployment recommendations to bring alternate footwear to swap out after duty hours and reinforcement in-theater could help to limit issues associated with total time in boots. It goes without saying that properly sized boots with adequate arch support are a necessary key to the success of any of the other recommendations. Should the built-in insoles have insufficient support, encourage the purchase of alternate arch supports off the shelf or as custom orthotics.⁷ Lastly, since blisters were reported in 10.9% of the base population (44% of those who reported foot problems), be prepared to provide an adequate supply of “mole skin” and ensure a liberal distribution policy.

TABLE III

General Principles for Deployed Foot Care

Principles for Deployed Foot Care

Make sure you have a good fitting pair of shoes or boots

Make sure you have a second pair

Make sure they are broken in

Try to have a different heel height between them

Be sure there is a good arch support: if not purchase an insert

Look for a boot with a well-cushioned sole and heel strike area

Use socks that breathe: preferably cotton or newer “wicking” materials

Get out of your shoes/boots as often and as much as possible

Keep your feet as cool, clean, and dry as possible

If necessary, swap out socks during a shift

Wash your feet well and pay attention between the toes

If spending long hours in a hot environment, use athlete's foot powder in anticipation of problems

Lace boots up tightly enough to avoid movement within the boot

Avoid friction and pressure points: consider use of “mole skin”

If necessary, use a second pair of socks, “mole skin,” band-aids, or corn pads, etc. to relieve friction and pressure points

A good soak with one-half of a cup of Epsom salts to 1 quart of hot water is therapeutic for sore aching feet

Avoid dry, cracked skin with the regular application of a moisturizing lotion

If you suspect you have a problem or it is getting away from you, be sure to get to sick call and have the issue properly dealt with early

 

REFERENCES

 

1. Bush R, Brodine S, Schaffer R The association of blisters with musculoskeletal injuries in male marine recruits. J Am Podiatr Med Assoc 2000; 80: 194–8.

 

2. Reynolds K, Darrigrand A, Roberts D, et al. Effects of an antiperspirant with emollients on foot-sweat accumulation and blister formation while walking in the heat. J Am Acad Dermatol  1995; 33: 626–30.

 

3. Merck Manual Hyperhidrosis 2006 . Available at http://www.merck.com/mmpe/sec10/ch118/ch118c.html; accessed December 13, 2006.

 

4. Thomas I, Brown J, Vafaie J, et al. Palmoplantar hyperhidrosis: a therapeutic challenge. Am Fam Physician  2004; 69: 1117–20.

 

5. Oumeish O, Parish L Marching in the Army: common cutaneous disorders of the feet. Clin Dermatol 2002; 20: 445–51.

 

6. Sadat-Ali M Plantar fasciitis/calcaneal spur among security forces personnel. Milit Med 1998; 163: 56–7.

 

7. Hockenbury T Forefoot problems in athletes. Med Sci Sports Exerc 1999; 31(7 Suppl): S448–58.