A Survey Analysis of Overuse Injuries in Recreational Recumbent Cyclists

by Randy Ice and John Waite

Fifty-five out of 142 male and female recreational recumbent cyclists, from a Lightning Cycles owners group, responded to a mail questionnaire. Dato on overuse injuries from this survey and a similar survey published on recreational cyclists using stand using upright bikes was compared. Overall 60% of the recumbent cyclists, compared to 85% of the standard cyclists, reported one or more overuse injury. The most common sites for overuse injury complaints were delineated for the recumbent cyclist and then compared to the complaints of the standard cyclist. When compared to the standard cyclists, the recumbent cyclists reported a significantly lower number of complaints in the areas of knee (recumbent 25.5%, standard 41.7%, p=0.078); back (recumbent 9.3%, standard 30.3%. p=0.002); hands (recumbent 9.1%, standard 31.1%, p<0.001); and neck (recumbent 7.3%, standard 48.8%, p<0.001).

Keywords: Recumbent, Cycling, Overuse, Injury

It has been estimated that there are over 52 million Americans involved in cycling.^[1] This includes 3.5 million who participate in recreational events, 240 thousand competitive cyclists, 4 million cycle commuters, 1.5 million cycling tourists, and 20 million mountain cyclists.^[1]

Literature on cycling injuries is extensive and well defined, addressing accidents, weather related conditions, heat, cold, dehydration, and overuse injuries, with the majority of injuries related to accidents.^{[2, 3, 4]} Kiburz et al^[2] reported that bicycle accidents comprised the greatest recreational source of emergency room visits in 1986. Not surprisingly, therefore, most of the research has addressed accident-related injuries such as fractures, head trauma, evaluation of protective bead gear, and collision-type accidents resulting in disabling injuries.^[4] Most of the additional research on recreational cycling has been with regards to the elite athlete.^[5] Weiss^[6] investigated overuse injuries of recreational cyclists involved in long-distance training. Recently, Wilbur et al^[7] published the results of an epidemiological analysis of overuse injures in recreational cyclists. The study effectively delineated the incidence and type of injuries reported by recreational cycling. However, no definitive research studies focusing on the incidence of overuse injury in the recreational recumbent cyclist have been conducted.

Nearly all recreational athletes will at one time or another experience some degree of injury, either traumatic or due to overuse.[8] The repetitive motion associated with sport activity frequently leads to tissue breakdown, or overuse injury, which can ultimately limit the athletes ability to cominue participating in their chosen sport, or activity. A recent study, published in the International Journal of Sports Medicine,^[7] specifically addressed the epidemiology of overuse injuries in the recreational cyclists. The findings in the study indicated that the neck, knees, groin/ buttocks, hands, and back were the most common areas of complaint in recreational cyclists, and reported the frequency of these injuries. In the past several years many recreational cyclists have been changing iheir riding habits to recumbent cycling. Many of these riders have anecdotally reported that riding the recumbent bicycle is more comfortable, leads to less pain and injury, aod consequently provides greater eajoyment to the rider. A thorough search of the available literature produced no research in the area of overuse injuries associated with cyclists utilizing a recumbent bicycle for the majority or all of their cycling.

The purpose of this study was to define demographic and behavioral characteristics of the recreational recumbent cyclist, delineate injury risk and associated training factorc describe training problems, delineate equipment, and draw comparisons on the incidence of injury between recreational recumbent and standard cyclists. For the purpose of this study a recreational recumbent cyclist was defined as an individual who used a recumbent bicycle for greater than 75% of their training, participated in recumbent cycling at least one time per week, and did not compete in events other than recreational fun rides.

Methods

Subjects

Subjects for the study were obtained from a list provided by SCOR Productions, a bicycle riders club, and a representative of the Bicycle Riders Directors Organization. All of the subjects who received the questionnaire were subjects who had indicated in previous correspondence the use of a recumbent bicycle for the majority of their training. Questionnaires were mailed to 142 male and female recumbent cyclists.

Questionnaire

A previous study by Wilbur et al^[7] demonstrated the efficacy of a questionnaire for the specific purpose of addressing the training characteristics and injuries to the recreational cyclist. The questionnaire used in this study was modified slightly in format to specifically address the recumbent cyclist but was essentially identical to the one used in a study by Wilbur et al.^[7]

The questionnaire was divided into three major areas:

1. demographics, including age, gender, height, weight, education, smoking history, and diet;
2. training characteristics including pace, frequency, duration, intensity, warm-up and cool-down, years of cycling, cycle event participation, other sport participation, terrain and cycle equipment (e.g.: number of gears, bipedal system, use of helmet, and padded shorts);
3. an examination of incidence of injuries, examining history, type, frequency, cause, and severity.

Overuse injury was defined as any self reported injury described by bruising, pain, swelling, discomfort, in any of the addressed body locations. Severity of injury was classified on a scale of 1-3. A(1) indicated pain but continued cycling. A(2) was used by the cyclist to report reduced training due to the injury. A(3) was defined as pain severe enough to prevent the cyclist from cycling at all due to symptoms.

Data Analysis

Data was analyzed using the WinSTAR computer program for statistical analysis. Chi-Square tests for homogeneity were used for comparing results between standard and recumbent cyclists by body site.

Results

The questionnaire was sent to 142 male and female recumbent cyclists. Fifty-one males and four females returned the questionnaire demonstrating a 39% response rate to the mailing. Males accounted for 93% of the responses. The mean age, height, and weight of all respondents were 41.3 years (SD 7.5), 70.5 inches (SD 3.1), and 170.3 pounds. (SD 3.1). For educational level of the respondents indicated high-school (3.6%), technical/occupational (12.7%), college (49.1%), and graduate school (34.5%).The vast majority of the cyclists reported non-smoking (70.9%). A great number of the respondents indicated special dietary and nutritional plans consisting of low fat/cholesterol (40.0%); low salt (21.8%); high calorie (30.9%); vegetarian (9.1%); and decreased calorie (7.3%). (Table 1)

Equipment characteristics cycling habits

The majority of the cyclists reported owning a recumbent cycle (90.9%), 27.3% reported owning a mountain bike, 29.1 o/o owning a touring/racing bike, 7.3% using a hybrid bicycle. The mean number of gears was 19.9 (SD 2.3). Pedal preference was varied with 32.7% of the respondents indicating use of a touring shoe or other shoe with toe clips and straps. The majority of the recumbent cyclists reported using an clipless pedal and shoe (50.9%). Protective head gear was reported worn by nearly all of the cyclists (85.5%). (Table 2)

Cycling habits

Data from 17 cycling characteristics (miles/week, days/week, average miles per hour, type of cycling, including distinctions between easy, mild, moderate, hard, and very hard; hills, no hills, or combinations; and heart rate monitoring) are summarized in Table 3. The cyclists reported a mean number of events per year of 1.8 with a large standard deviation of 2.0 indicating a broad variability in the responses to this inquiry. A majority of the cyclists also reported participation in other activities (71.0%). (Table 3)

Traumatic accidents while riding the recumbent bicycle

Traumatic accidents while riding the recumbent cycle were reported by the cyclists. (Table 4) Twelve of the riders who responded indicated being involved in a traumatic accident in the past one year. All of those who indicated an accident in the past year reported a single-rider incident including 16.7% having a collision with a car, with 58.3% receiving medical attention, and 71.4% seeking the advice ofa physician. Eight of the cyclists (mean 3.4, SD 7.2) indicated being bitten by a dog, with 18.2% seeking medical attention. Collisions with animals had occurred an average of 1.8 times (SD 1.5). Eight respondents also indicated being hit by a foreign objects (mean 2.5 and SD 2.8).

Injuries from other sports

A majority of the cyclists reported injuries from running (69.2%) with another 30.8% indicating injuries from a wide variety of other athletic activities. Approximately one out of five of the recumbent cyclists (21.8%) reported switching to a recumbent bicycle from a standard cycle due to injury. Recumbent cyclists also reported switching to a recumbent cycle for reasons other than injury specifically: comfort (52.7%), pain relief (27.7%), speed (12.7%), safety (9.1%) and efficiency (7.3%). An additional 18.2% were riding a recumbent bicycle due to medical problems.

Overuse injuries by anatomic sites

The knees represented the largest complaint of pain, stiffness and/or general discomfort, with 25% of the cyclists reporting these symptoms. The second most common site of injury was the groin/buttocks region with 23.6% of the cyclists reporting pain or discomfort while riding. Feet represented the third most common area of complaint with 21.8% of the recumbent cyclists reporting pain, numbness, or tingling while riding. The fourth area of complaint was the lumbar spine representing 9.1% of the respondents with complaints of pain, and stiffness with riding. Complaints of discomfort in the hands were reported in 9.1% of the cyclists. Hips, neck, shoulders, and thigh were each reported as areas of pain and/or discomfort while riding by 7.3% of the respondents. The incidence of injury in the remaining areas of Achilles, head, elbow, and ankles were much lower, or none.

Relative incidence of injuries between recumbent and standard bicyclists

Only 7.3% of the recumbent cyclists reported complaints of neck pain compared to 48.8% of the standard recreational cyclists. Low back pain was reported in 9.3% of the recumbent cyclists and 30.3% of the standard cyclists. Hand pain and discomfort was reported in 9.1% of the recumbent cyclists while it was reported in 31.1% of the standard cyclists. Twenty-five and one-half percent of the recumbent cyclists reported knee pain while 41.7% of the standard cyclists reported knee pain. While 23.6% of the recumbent cyclists reported groin/buttocks pain compared to 31.6% of the standard cyclists, the limited population studied with regards to the recumbent cyclists rendered this finding non- statistically significant. A similar inquiry by Wilber et.al.[] for standard bicyclists reported findings on the same areas of injury discussed in this survey. A comparison of the relative incidence of injury in the recumbent cyclist as compared to the recreational cyclists riding standard bicycles is shown in Table 5. Recumbent cyclists reported significantly less injuries than recreational standard cyclists in a number of different sites: low back (p=0.002), neck (p=0.000), hands (p=0.001), and knee (p=0.028), on Chi-Square analysis. Groin/ buttocks pain, while reported less often, was not significantly different (p=0.28).

Discussion

Previous studies of the incidence of injury among cyclists have largely focused on the competitive cyclist. The study by Wilber et.al.[7] was one of the first studies to address, epidemiologically, the incidence of injury in the recreational cyclist. Their findings described the major areas of injury to be the back, neck, groin/buttocks, hands, and knees and their incidence related to the population of recreational cyclists.

It has long been suspected that the increased use of recumbent cycles in the cycling world has been due to less injury, greater comfort, and better performance. However, to date we know of no study which had addressed these assumptions to determine their accuracy. This study sought to identify which anatomical locations presented with the greatest injury complaints for recumbent cyclists, and to compare these findings to the findings in the study on recreational cyclists.

The findings demonstrate that in the majority of the anatomical areas of low back, neck, hands, and knees, the incidence of injury was significantly less in recreational cycling on a recumbent bicycle than recreational cycling on a standard bicycle.

Certainly the anatomical position differences that the recreational and recumbent cyclist are placed into while riding represent the largest contributing factor to the types and incidence of injuries noted in the two studies. Biomechanically, the standard bicycle places the rider in a position which inherently leads to additional stress to the low back, hands, knees, and neck. The groin/buttocks area is involved in both of the different types ofriding and would probably be better split into two separate categories in future studies. Also with fifty-five respondents in the study, the findings are limited in scope. A larger study taking into account different regions of the country and a better response rate would greatly improve the applicability to the general population.

The recreational cycle is not without risk. The possibility of collisions either with other riders, automobiles, stationary objects or other environmental hazards remain. However, this study demonstrates that in a number of anatomical areas the incidence of injury is significantly less when riding a recumbent bicycle.

Table 1: Demographics

Gender

Education

Smoking

Diet and nutrition

Table 2: Type of cycling equipment

Type of bicycle

Number of gears

Type of pedal system

Protection

Table 3: Cycling Habits

Miles/week

Days/week

Average MPH

Type of cycling

Activity level

Heart rate monitoring

Table 4: Traumatic accidents while riding recumbent bicycle

Hazards encountered

Injuries from another sport

Table 5. Relative incidence of injuries between Lightning cyclists and recreational cyclists

* Second study shows 12.8% after 1 month adaptation

REFERENCES

1. Bicycle Federation Of America. Facts and Figures about bikes and bicycling. Washington, D.C., 1991.
2. Kiburz D., Reckling J., Jacobs R., Mason J.: Bicycle accidents and injuries among young adult cyclists. Am J Sports Med 14:416–419, 1986.
3. Wasserman R.C., Buccini R.V.: Helmet protection from head injuries among recreational bicyclists. Am J Sports Med 1990 Jan-Feb; 18(1):96–7.
4. Thompson R.S., Rivara F.P., Thompson D.C.: A case study of the effectiveness of bicycle safety helmets. N Engl J Med 1989 May 25; 320(21):1361–7.
5. Hopkins S., McKenzie D.: A survey ofoveruse injuries in elite cyclists. Unpublished doctoral dissertation, University of British Columbia, Vancouver B.C., 1990.
6. Weiss B.: Nontraumatic injuries in amateur long-distant bicyclists. Am J Sports Med 13:189–192, 1985.
7. Wilber C.A., Holland G.J., Madison R.E., Loy S.F.: An Epidemiological Analysis Of Overuse Injuries Among Recreational Cyclists. Int J Sports Med 16:201–206, 1995.
8. Collins K., Wagner, M., Peterson K., Storey M.: Overuse injuries in triathletes. A study of the 1986 Seafair triathlon. Am J Sports Med 1989 17(5):675–80.
9. Bohlman J.: Injuries in competitive cycling. Physician and Sports Med 9:117–124, 1981.
10. Davis M., Litman T., Crenshaw R., Mueller J.: Bicycling injuries. Physician and Sports Med 6:88–96, 1980.
11. Dickson T.: Preventing overuse cycling injuries. Physician and Sports Med 13:116–123, 1980.
12. Kunlund D., Brubaker C.: Injuries in the Bikecentenial Tour. Physician and Sports Med 6:74–78, 1978.
13. Mellion M.: Common cycling injuries management and prevention. Sports Med 11:52–70, 1991.

Credentials

John Waite M.P.T. is owner/director of Rancho Physical Therapy in Murrieta, California. He specializes in rehabiliation of the injured athlete. Graduated from California State University Northridge in 1990 with a B.S. in physical therapy. John recently completed an advanced master of physical therapy from Loma Linda University, and is currently a doctoral candidate in physical therapy also from Loma Linda University.

Randy Ice P.T., C.C.S., is owner/director of Lynwood Physical Therapy in Lynwood, California. Randy is board certified in cardiopulmonary rehabilitation, and has published over 70 articles in the field of endurance training and cardiopulmonary rehabilitation, with an emphasis in cycling. A former instructor in cardiac rehabilition in the physical therapy program at U.S.C., Randy now uses his expertise to direct the Center for Cardiopulmonary Rehabilition for Rancho Physical Therapy in Murrieta, California.

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