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| Feature | No.61 May 2011 |

The International Paralympic Committee Classification Code: Solid Foundation or Built on Sand?
Colin Higgs
Introduction
The Governing Board of the International Paralympic Committee (IPC) approved a Classification Strategy in 2003, which recommended the development of a universal Classification Code. The IPC Classification Code is designed to be a high level overview of requirements and best practices. In compliance with the Code, individual International Sport Federations (IFs) are responsible for the development and application of their sport specific-classification systems (see Figure 1).
Figure 1. IPC Classification Chart
The Classification Code was developed between 2003 and 2007 and was approved by the IPC General Assembly in November 2007. The purpose of the code(1) was, and remains, to “ensure that an Athlete`s impairment is relevant to sport performance and to ensure that the Athlete competes equitably with other Athletes”.
These two stated purposes therefore require a detailed examination of:

- The relationship between impairment and sport performance, and
- The concept of equitable competition.

Impairment and sport performance
It is self-evident that, in general, higher degrees of impairment translate into lower levels of sports performance. However, the relationship is not linear and is specifically related to the technical and physical demands of the sport. Compare, for example, the impact of different levels of impairment on different sports. For ease of comparison let us consider different levels of impairment from either of two types of disability (spinal cord injury or amputation) in the sports of athletics (running), wheelchair basketball and archery (see figure 2).
In running, there is a progressive reduction in running performance as the athlete progressively loses function in the parts of the body below the ankle, then the knee and then the hip. With any greater degree of impairment, the sport activity becomes impossible.
In archery, an increasing level of impairment from ankle to knee to hip has a small impact on shooting performance, but with increasing impairment through the trunk region, accompanied by a loss of trunk mobility, there is a more rapid decrease in sport performance. Once the impairment involves the upper limb, reduction in performance decreases rapidly until the activity becomes impossible or near impossible.
In wheelchair basketball the relationship is somewhat more progressive.
Under the Code, there is a requirement for evidence based data explicitly linking sport performance to degree of impairment, and sports, through their International Federations (IFs) have undertaken (or are undertaking) this work. Their objective is to quantify the relationship and determine which components of impairment contribute to changes in sport performance. While doing this, there is also a need to ensure that the approved classification system, based on the relationship between impairment and sport performance, does not take away the desirable advantage that accrues to athletes who train harder and are better coached.
One difficult problem that this approach raises is that of untangling the complex interactions between genetic predisposition for athletic performance, degree of impairment and improvement through training. Any given sport action can potentially be achieved in different ways, and each individual athlete, will perform the desired action with a unique combination of (a) genetically determined athletic potential, (b) the cumulative effects of years of training and (c) the athlete`s degree of impairment. Methods for separating the relative contribution of these three factors have not yet been established, and this remains a classification system weakness.
Figure 2: An idealised model of the impairment-sport performance relationship for three different sports
Hidden Assumptions underlying classification systems
There are a number of key assumptions that underlie much of the evidence-base for classification systems, of which some of the most important are assumptions about body-symmetry, inter-event homogeneity, and equipment independence. It should be noted that these assumptions do not apply equally to all sports.
The assumption of Sport Symmetry
There is an underlying assumption that sport is symmetrical; that is, that what the left and right side of the body can do in sport is identical and are mirror images of each other. In able-bodied athletes, this assumption of symmetry overwhelmingly holds true since there are few discernible differences in the structure and biomechanical performance of the left and right sides of the body. Where such differences exist due to the hand-dominance preferred by the athlete, there is the ability in almost all sports for the athlete to perform either right or left handed.
While many sports for persons with a disability are bi-laterally symmetrical - the left and right sides of the body performing identical actions - others are not, and this has the potential to create different impairment-sport performance relationships for athletes impaired on the left or right side of the body. Contrast, for example, sprinting in swimming and athletics.
In the pool the athlete has the option, on the starting blocks, of leading with either foot; and a left-foot push-off is functionally identical to a right-foot push-off. The pool is symmetrical and the swimmer moves only in a straight line. An athlete with a below-the-knee right-leg amputation has the same relationship between impairment and potential for sport performance as the below-the-knee left-leg amputation. The same is true for athletes in the pool who have arm impairments.
On the running track, however, things are different. Running tracks are oval(2) , and all events longer than 100m take place on the oval or the curved portion of the oval, with the runner always making a left-turn to stay in his or her lane. With the running path asymmetrical, it is therefore interesting to speculate on whether impairments to the left and right sides of the body have the same impact on sport performance.
There is a paucity of empirical data on running speeds “around the curves” of left-leg vs right-leg amputees. However, there are good theoretical reasons why the loss of the leg on one side of the body might place the runner at a disadvantage. Two well-substantiated observations lead to this conclusion.
First, there are unavoidable physical laws which dictate that the runner must “lean in” towards the inside of the curve to counteract the centrifugal force generated by the motion of running a curved path. The amount of lean required for balance depends on the speed of running(3) and the radius of the turn (making this more of a problem for those on the inside lane as opposed to those on the outside lane). Since 200m races are the fastest curve-running events, the lean-in is greatest at this distance.
Secondly, there is the observation that among single-leg amputees there is frequently a lifting of the hip on the side of the body on which they are required by the rules of track and field to run in a counter-clockwise direction around the track, it is interesting to consider whether a left-leg or right-leg amputation confers any advantage. When running counter-clockwise around the track, the runner leans to his or her left to counteract the centrifugal force generated. This in turn tilts the hip slightly so that the outside (right) hip is higher than the inside (left) hip. The higher hip position means that a prosthetic limb can swing-through with a minimum of deliberate right-hip lift. Conversely, if the runner has left-leg prosthesis and is also leaning to the left, then the deliberate hip-lift to permit the prosthesis to swing-through will need to be greater than if running in a straight line.
The hypothesis (that needs to be experimentally tested) is therefore that a right- leg amputation confers an advantage (see Figure 3). There are other sport activity examples in which asymmetry may play an important role. Staying with Track and Field, consider, for example the standing throws. In the standing throws, lower-limb impairment may be asymmetrical, meaning that the lower-limb impairment can be on the same side of the body as the throwing arm, or can be on the opposite side. Since the leg action in all of the throwing techniques is known to be asymmetrical, it is reasonable to assume that same-side, and opposite-side lower limb impairments will not have the same impact on sport performance. In one widely used shot-put technique, for example, a right handed thrower will start bent from the waist with all of their weight supported by the right leg. The right leg is then used to glide across the throwing circle, to generate body speed that can be added to the speed imparted to the shot by the trunk and then the shoulder/arms. This provides an inability to generate this gliding speed which will in turn impact throw velocity and therefore the distance of the throw.
There is also a different issue related to running symmetry, and that is the changing relationship between sport performance and single versus double amputation. Historically single amputees outperformed double amputees, but with development of prostheses that store and return energy, this has changed. Modern prostheses return more energy to the runner than a natural leg, and there is now some belief that, from a sport performance perspective, the double amputee now has an advantage.
The assumption of intra-sport, inter-event homogeneity
When athletes are classified for participation in a sport, there is an underlying assumption that the same relationship between impairment and sport performance holds for all events within the sport. This may not be true, and requires empirical investigation by IFs that have multi-event sports. In swimming, for example, issues of muscle control might be more important in sprints than in distance events given the different contribution of power and endurance to sprints and distance events. If this is in fact the case, the Code requirement for equitable competition essentially demands an event-specific classification system within the sport.
Figure 3. Track running on a curve, and its relationship to hip-lift
The Assumption of Equipment/technique independence
In classification, there is also an assumption that the impact of impairment on sport performance is independent of the equipment used. Again, this assumption may not be correct. Two examples clarify the relationship.
Progressively greater trunk stability has been achieved in wheelchair racing and sit-skiing through the development of chair “bucket” designs in which the structure of the wheelchair or sit-ski seat prevents trunk movement and therefore reduces the impact of trunk instability through muscle loss and the potential performance difference between sports classes with different degrees of truck instability. Potential future integration of seat and supportive-clothing design could push this development even further. A second example is the invention in the 1980s of backhand wheeling techniques by tetraplegics - an invention that significantly reduced the sport performance differences between the then existing wheelchair racing classes.
The unanticipated consequence of this interaction between the impairment - sport performance relationship and technique and equipment is that to maintain a fair and equitable classification system, it will need to be re-evaluated every time a new type of equipment or updated performance technique is developed.
It should be noted that the responsibility for investigating the impairment-sport performance relationship falls clearly to the International Federation responsible for the sport in question. However, some guidance from the Code concerning what could/should be taking into consideration, and how frequently classification systems need to be updated, would be valuable.
The concept of equitable competition
The Code requires International Federations responsible for a sport to ensure, “that the Athlete competes equitably with other Athletes”. However, in a system of competition that declares victors and celebrates elite performance, the concept of equitable competition is essentially an oxymoron.
The meaning of the term “equitable” has been subject to considerable debate, particularly in the areas of gender and employment equity. It is differentiated from the concept of “equal” in one fundamental way. In equal competition, everyone starts with the same rules, regulations and under the same conditions, and this is the case for events at World Championship or at the Olympics. The suitability of a particular individual for participation in a specific event is of no concern in a system of equal competition. Those who are best suited by way of body morphology, inherent talent, genetic predisposition, or dedication and desire win - and those who lose out in the genetic lottery for that even are out of luck.
In a truly equitable sport system, the way sport is conducted would be modified so that, regardless of level of impairment, each athlete would have a fair, equal, chance of being the victor. Elsewhere (Higgs, 2005) it has been demonstrated mathematically that, in ANY system of classification in which a continuum of impairment is divided into ANY number of discrete Classes:

- There will be no way in which the athletes with the greatest impairment within a class can compete equitably with those within the same class who have the least impairment, and
- There will be some athletes in a DIFFERENT class closer in level in impairment, than the level of impairment of some athletes in the same class .

Given that these two statements can be proven (in the true sense of a logical proof) then it becomes clear that the Classification Code is built on a shaky foundation. If, however, the Code were to proclaim its purpose to be something along the lines of, “Recognising that competition can never be equitable, the purpose of the Code is to define the degree of inequitable competition compatible with the ideals of the Paralympic Movement and the development of a robust and well accepted system of competition” then it would be an much firmer ground.
Conclusions
In its current form, the IPC Classification Code serves as a meaningful foundation for the evolution of Sports-Based Classification Systems by International Sport Federations. It rightly places the emphasis firmly on:

- The International Sports Federations being the groups best positioned to investigate and understand the relationship between level of impairment and sport performance in their specific sport.
- The need for any classification system to undertake empirical investigations to understand and describe the sport-specific (perhaps even event specific) relationship between impairment and sport performance.

What the Code fails to address (and in so doing places a burden - without guidance - on the IFs) is the degree of inequity in competition (caused by the inherent inequity of dividing a continuum of impairment into discrete, non-overlapping Classes) that is compatible with IPC ideals of competitive fairness.
International Federations have made great strides in moving classification from a medical model to a far more appropriate sport-based model, but have not fully thought through the underlying assumptions of their system. Indeed, the Code is a good foundation for future development, but, like any new edifice, there are a few early cracks in the foundation, that can be, and should be, fixed. When fixed, the `Code` will give classification the long-term stability it so badly needs.
Notes
(1) IPC Classification Code, Paragraph 2.1.1, Page 7
(2) Technically an oblique straight oval
(3) Specifically to the velocity of running squared
References
International Paralympic Committee (2007). The Classification Code. IPC Handbook, Section 2, Chapter 1.3. Available at: (www.paralympic.org/sport/Classification) (accessed 25th April 2011).
Higgs, C. (2005). The theoretical problems of classification systems. In `The Proceedings of the 2005 VISTA Conference`, Bonn, Germany.
Contact
Prof. Dr. Colin Higgs
Memorial University of Newfoundland
School of Human Kinetics and Recreation
St. John`s, Canada
Email: chiggsconsulting@mac.com

http://www.icsspe.org/