Bicycling participation in people with a lower limb amputation: a scoping review

In general bicycling has a number of physiological [1‐4] and psychosocial benefits [5, 6]. Bicycling can, for instance, lower the risk of non-communicable diseases such as cardiovascular disease [1‐3] and type 2 diabetes [7, 8]. Bicycling is thought to improve quality of life [9, 10]. People with a lower limb amputation (LLA) can also experience these benefits [9‐11]. In addition, an increase in muscle strength of the intact and amputated limb as a result of regular bicycling [12] resulting in better walking [13, 14]. It is for the above mentioned reasons that enhancing the ability to perform physical activity (PA) such as bicycling for people with a LLA is important.

Bicycling is a low-impact activity as most of the body weight is supported by the bicycle’s seat, and consequently relieving the load on the residual limb in people with a LLA. But bicycling requires more degrees of flexion at the hip, knee and ankle than walking [15, 16] which could be limited by designs and functions of prosthetic components. Some reviews have been performed to gain information on barriers and facilitators in PA or sports participation in the group of physically disabled persons and people with a LLA, but not focusing on bicycling [17, 18]. One review provided a way to adapt prostheses and bicycles for bicyclists with a transtibial amputation (TTA), however, no information for other levels of LLA nor were participation rates reported [19]. Another review on bicycling for different amputation levels of lower and upper limbs included studies without people with a LLA and included studies with people cycling on ergometers [20]. These inclusions limit clinical relevance of outcomes of that review [20].

Assessment of bicycling participation, and associated facilitators and barriers can identify the needs of people with a LLA. That insight can assist clinicians and researchers to design interventions that meet with the clients’ goals and perspective and therefore may improve the participation in bicycling. Since bicycling has benefits, but information on participation in people with a LLA is lacking, the aim of this scoping review is to investigate and summarize bicycling participation rates in people with a LLA. The prevalence, frequency, duration and reasons for bicycling were identified. The second aim is to evaluate facilitators and barriers for bicycling in LLA.

Health benefits from bicycling are apparent and bicycling serves as an alternative to other modes of transportation and exercise for LLA. After all, unlike running, skiing or golfing, recreational bicycling requires very little modifications to the people with a LLA to participate. Bicycling should remain an integral component of rehabilitation and the return to recreation and vocation [82]. Bicycling participation ranged from 4 to 48%. Two studies done in the same country reported considerable differences within a country [34, 37]. People with a LLA bicycled for reasons of transportation, recreation, sport and physical activity [27, 32‐37]. Data about frequency and duration of bicycling were not found from the included studies. Since most studies aimed to determine changes of lifestyle or activities after LLA, intensity, duration and frequency of PA were reported for the big picture of attended activities but not specifically for bicycling [34, 37].

In this study, we assumed that the studies are about bicycling outdoor if it was not specified in studies [32, 34‐37]. There is one study that the term bicycling referred to both indoor and outdoor bicycling [34]. When participation rate was reported, two studies reported sport participation if a minimum duration of half an hour for each participation [36] or total of 5 hours participation a month [35] was met. Whereas, in 5 studies, duration was no concern as long as the people with a LLA reported riding the bicycle [27, 32‐34, 37]. Consequently, the participation rates should be interpreted with caution. Definitions of bicycling participation should be reported in future studies.

The majority of participants in the included studies were males with a TTA or TFA. Males with a TTA were reported to participate in the bicycling the most. The overall gender distribution of people with a LLA is about 50% male and female [83]. Therefore, including considerably more than 50% of male participants or veterans in studies [34, 37] may not represent the general population of people with a LLA. Although male, distal level of amputation and amputation due to trauma may associate to higher level of bicycling participation, the results of this review may not reflect the interest and purpose of bicycling of general populations with a LLA.

Bicycling was chosen as a form of transportation in Slovenia besides using cars and public transportations and was related to the level of independence [33]. A study from India investigated the functional capabilities of people after LLA and only included essential activities for daily living, vocational activities, and living arrangements in which bicycling was surveyed. It was demonstrated that bicycling was an important mode of transportation for civilians in India [27]. Both studies were done some decades ago; however, the recent studies did not show a difference in favor of other transportation modes in India especially in the group of low-income people [84, 85]. Socioeconomic status such as income or occupation may influence traveling by bicycling. A small number of participants could not ride the bicycle even before the amputation [27]. Knowledge or skill may facilitate bicycling participation. Two studies showed older age and longer time span after amputation [33] and level of LLA [27, 33] related to the reduce or stop traveling by bicycling. A change in lifestyle after the LLA was also reported in which bicycling became less popular after the LLA [29]. Disability, health, lack of energy and fatigue were personal barriers which were reported in a previous review of sports barriers and facilitators in adults with different types of physical disabilities [17]. It is possible that older people or a more proximal level of LLA may have more disabilities, health problems, less energy or more likely to be fatigue during bicycling. In contrast, for recreational bicycling, an equal number of veterans with a TFA and TTA was reported [34]. The relationship between amputation level and cause, these barriers and bicycling participation should be further studied.

Factors influencing competitive or high intensity bicycling were done in specific groups of bicyclists- TTA or Van Nes rotationplasty. Most studies investigated a small group of participants, mainly male, and having different bicycling experience [26, 28‐30, 38, 39]. Only one study utilizing data of more than 8 participants (N = 41); however, the same participants were analyzed more than once [31].

For bicyclists with a TTA, the focus of research was towards asymmetry in force and work between sound and amputated side and ways to reduce this asymmetry for better performance [26, 28, 29]. Clinically, a STIFF foot reduced the pedaling work asymmetry in high-intensity or competitive bicycling [29] but not in recreational bicycling. In low-difficulty bicycling, no significant difference were found between the STIFF and the Flex foot suggesting a walking prosthetic foot may be adequate for recreational bicycling [29]. A pylon with an aerofoil shape caused less aerodynamic drag than the round shape [30]. On the one hand, a prosthetic foot and pylon influenced high intensity bicycling. On the other hand, while comparing between prosthetic and non-prosthetic bicyclists, there were no significant benefits reported from the prosthesis to the athletes [31]. Besides the kinetic asymmetry, there were hip and knee kinematic asymmetries which were reduced by shortening of the crank arm length on the amputated side [26]. The shortened crank arm also reduced the muscles activity on the amputated side [26]. Although the shortened crank arm improved the asymmetry in the person with a TTA in a case report [26], the same shortening may not give the same effects to other people with a TTA.

For a person with Van Nes rotationplasty, the socket design of walking prosthesis was a bicycling barrier because it caused skin abrasion [39]. Adding a hinge to the crank arm enabled a person with Van Nes rotationplasty with limited knee range of motion to bicycle [38]. Adaptation of the socket and crank arm might also facilitate bicycling in people with other types of LLA who have skin abrasions or limited knee ranges. The biomechanical effects from the prosthetic feet and crank arm shortening [26, 28, 29, 38] were also reported in a previous review of cycling with an amputation [20]. That review focused on upper and lower limb amputee biomechanics, physiology, and assistive technology development and extracted data from expert opinions, reviews, and primary researches from 2004 to 2014 [20]. Articles without any participants and studies using ergometers were included [20], while the current review included only primary research of at least one human with LLA riding a normal bicycle from all publication years. Therefore, the objectives, methods and results of the previous review differ from the current review.

The personal factors for transportation by bicycling were age, time since LLA, and level of amputation. The prosthetic socket design can either be an environment facilitator or barrier for high-intensity bicycling. The STIFF foot and crank arm shortening were environmental facilitators for high-intensity bicycling. For people with a knee flexion limitation, the limitation was a personal barrier and the hinged crank arm was an environment facilitator. Other bicycling environment factors such as weather, cycling paths, physical and emotional support, individual and societal attitudes toward people with a LLA, public services, systems or policies were not reported.

Multiple purposes of use of bicycles are exhibited in this study. After LLA, people stopped bicycle or changed leisure activity. Age, level of LLA, and time since LLA influenced bicycling participation. Although environmental factors were limited to prosthetic socket and pylon design, foot stiffness and bicycle’s crank arm, arisen predominantly from small groups of bicyclists with a TTA and Van Nes rotationplasty, and mainly benefit to competition, some practical advices can be given. For instance, prosthetists may try to shorten the crank or use stiff foot if pedaling asymmetry is present. To supply prosthetists with sufficient additional knowledge in compiling an optimal prosthesis for bicycling, more research is necessary. Efforts towards studying facilitators and barriers for bicycling in a population with a LLA who are not athletes can benefit the general population with a LLA [9‐14]. Further investigation of prosthetic and bicycle components in either competitive or recreational bicycling should include more participants, thus providing strong evidence for implementations by prosthetists or sport scientists.