Too Tall to Race? Blake Leeper, World Athletics and the MASH Rule

Timeline

1. Jan 2018The IPC implements the MASH (Maximum Allowable Standing Height) method for double amputees.
2. Aug 2018Leeper undergoes biomechanical testing at a University of Colorado Boulder lab.
3. 18 Feb 2020World Athletics denies his application to use his prostheses in Olympic qualification.
4. 26 Oct 2020CAS rules the burden of proof must fall on World Athletics, but finds his prostheses give an overall advantage.
5. 24 Dec 2020Leeper applies to run on shorter prostheses.
6. 26 Apr 2021World Athletics' Mechanical Aids Review Panel rejects the new application.
7. 2 Jun 2021The Swiss Federal Tribunal dismisses his challenge to the first CAS award.
8. 11 Jun 2021CAS dismisses his second appeal, days before the US Olympic Trials.

The ethical issues

• Who must prove advantage or disadvantage.
• Fair comparison between prosthetic and biological legs.
• Whether eligibility formulas carry racial bias.
• Inclusion of disabled athletes in open competition.
• Use of science under uncertainty.

Stakeholders

Stakeholder	Interests & obligations
Blake Leeper	Competing at the highest level on equal terms.
Able-bodied 400m runners	Confidence that races are fair.
Other amputee athletes	Clear, fair rules for prosthetics.
World Athletics	Defensible eligibility rules.
International Paralympic Committee	Valid classification methods.
Scientists	Their evidence being properly weighed.

The case

Background

Blake Leeper, an elite sprinter from Kingsport, Tennessee, was born without legs below the knee and runs on carbon-fibre running-specific prostheses, or “blades” ^[2]. In 2018, the University of Colorado Boulder reported, he ran 400 metres in 44.42 seconds, faster than Oscar Pistorius, who in 2012 became the first below-the-knee amputee to race at the Olympics ^[2]. With times like that, Leeper set his sights on the Olympics.

That August he went to a Colorado lab run by Alena Grabowski, a specialist in running prostheses, for tests at the start, at maximum speed, on curves and to exhaustion. The team compared him with more than 30 elite runners without amputations. They reported that he did not accelerate faster, reach higher top speeds, run curves as fast, or show better endurance. Grabowski said his prostheses put him at “a significant disadvantage bursting out of the blocks and rounding curves” ^[2].

The rules and governance

World Athletics’ Technical Rules (formerly IAAF rule 144.3(d)) prohibited “the use of any mechanical aid, unless the athlete can establish on the balance of probabilities that the use of an aid would not provide them with an overall competitive advantage over an athlete not using such aid” ^[1][7]. In other words, the athlete had to prove a negative.

The International Paralympic Committee (IPC) in January 2018 adopted the MASH (Maximum Allowable Standing Height) method for double amputees. It predicts a “natural” height from the lengths of the thigh, upper arm, forearm and sitting height, each weighted, and adds an error allowance of 1.91 cm. Blades that make an athlete taller than that are treated as giving an unnatural advantage ^[4].

Decision point: the first appeal

On 18 February 2020 World Athletics refused Leeper’s application to use his current prostheses in Olympic qualification. He appealed to the Court of Arbitration for Sport on 27 February ^[1]. On 26 October 2020, a CAS panel of James Drake QC, Klaus Reichert SC and Murray Rosen QC partially upheld his appeal. It ruled that the rule was “unlawful and invalid to the extent that it places the burden of proof upon an athlete,” so World Athletics had to prove an advantage ^[1].

But the panel found that World Athletics had proved one. His prostheses “enabled him to run at a height that was several inches taller than his maximum possible height if he had intact biological legs,” giving him an overall competitive advantage in the 400m. He could not use them in World Athletics-sanctioned 400m events, including the Olympics ^[1].

Grabowski called it “a discriminatory and unorthodox ruling.” Her collaborator Paolo Taboga pointed to a study published that year in PLOS ONE that found height makes no difference to top sprinting speed: “while you do take longer steps, you also cycle your legs slower so in the end, the two even out” ^[2]. Grabowski added that MASH was based on two studies with no Black subjects. “I will never give up,” Leeper said ^[2]. The Swiss Federal Tribunal later dismissed his challenge to the award, rejecting claims that it breached the prohibition of discrimination and human dignity ^[6].

Decision point: the second application

On 24 December 2020 Leeper applied to run on shorter prostheses giving him a standing height of 185.42 cm (6 feet 1 inch). World Athletics’ new Mechanical Aids Review Panel, chaired by David Grace QC, rejected the application on 26 April 2021, finding World Athletics had “satisfied its burden of proof on the balance of probabilities” that the blades gave him an overall advantage ^[3][4]. His appeal to CAS was dismissed on 11 June 2021 ^[4].

The CAS release gave the numbers: Leeper’s MASH height was 174.44 cm (5 feet 9 inches), about 10 cm lower than his height on the proposed prostheses. MASH was derived from a 2009 study of Caucasian athletes and validated with small groups in Japan and Australia, on the premise that geographic distance, not race, is the main driver of differences in body proportions ^[4]. The panel rejected Leeper’s argument that the method could not be sound until validated for Black athletes of African descent. But it noted the experts’ consensus that such validation would be “sound and desirable” and “strongly encourage[d]” World Athletics to do it. It also found no workable “less-intrusive alternative” to disallowing the blades ^[4].

Aftermath

Leeper’s lawyers said 6 feet 1 inch was “the same height as numerous other 400m runners, and the same height that Mr. Leeper uses in his day-to-day life.” They said World Athletics had relied on photos of athletes from the 1960 Rome Olympics, in which two of twelve Black able-bodied athletes would have exceeded MASH ^[5]. “It is tragic and wrong that World Athletics will be permitted to continue its discrimination against me and other Black disabled athletes,” Leeper said ^[5]. The ruling came just before the US Olympic Trials ^[5].

The core dilemma

Sport wants to include disabled athletes in open competition while ensuring that equipment does not do more than compensate for their disability. When the science is uncertain, and the measuring tool may not fit every body, who should bear the risk of error?

Competing values

• Inclusion vs. competitive fairness: open racing for disabled athletes against equal conditions for all ^[1].
• Burden of proof vs. practical regulation: the athlete against the governing body proving advantage ^[1].
• Scientific certainty vs. timely decisions: waiting for better data against qualifying deadlines ^[4][5].
• Uniform rules vs. population differences: one formula against varied body proportions ^[2][4].

Strongest arguments

For World Athletics: CAS found that it carried its burden on the evidence ^[1][4]. Some limit on blade length is necessary, or any athlete could choose a height. MASH gives a consistent, objective standard with an error margin ^[4]. Its validation premise was not contradicted by evidence in the case ^[4].

For Leeper: his lab results showed no advantage in speed or endurance, and a disadvantage at the start and on curves ^[2]. Height’s effect on sprinting speed is disputed ^[2]. Applying a formula never validated for athletes like him, at a critical time, risked discrimination ^[2][5].

On the first ruling: shifting the burden to the governing body was a real gain for athletes using aids ^[1].

Applying the frameworks

Justice

A justice lens asks whether the procedure was fair: who bears the burden, whether the evidence base covers all populations, and whether the timing allowed a fair chance ^[1][4][5]. It also asks whether a standard derived mostly from one group can justly be applied to another.

Rights

Rights thinking weighs Leeper’s claim to compete without discrimination against other athletes’ right to fair competition. The Swiss tribunal’s narrow review shows how hard such claims are to enforce against private sports bodies ^[6].

Utilitarian

A consequentialist would weigh the value of inclusion and of precedent for disabled athletes against the risk of an unfair advantage, and the costs of mistakes in either direction.

Walk it through: the Simple Decision Model

1. Identify the problem: does a set of prostheses give more than compensation for disability?
2. Gather the facts: lab data, height evidence and the limits of MASH ^[1][2][4].
3. Identify the stakeholders: Leeper, other runners, amputee athletes, World Athletics and the IPC.
4. Consider the options: allow the blades, cap height, or race in separate results.
5. Apply values and frameworks: inclusion, fairness and procedural justice.
6. Decide and review: decide on current evidence and commission validation for all populations.

What’s settled and what’s contested

Settled: CAS shifted the burden to World Athletics in 2020 but barred his prostheses; it upheld the second refusal in 2021 and urged validation of MASH for Black athletes ^[1][4].

Contested: whether height confers a sprinting advantage, and whether MASH is fair to athletes of African descent.

Why this case matters

Prosthetics cases test how sport defines a level field. Compare Markus Rehm: The Blade Jumper and the Olympic Long Jump, Oscar Pistorius: Prosthetics Eligibility and the Killing of Reeva Steenkamp and Caster Semenya and Testosterone Eligibility Rules.

Key terms

Equalizer vs. enhancer

Whether a technology or adaptation restores a level field (adaptation) or gives an advantage beyond it (augmentation).

Classification

The system adaptive and Paralympic sport uses to group athletes by functional ability so that competition is meaningful.

Reasonable accommodation

Adjusting conditions so people can take part, without lowering the standard. Fairness isn’t sameness.

Social model of disability

The view that disability comes not from impairment alone but from barriers, discrimination and exclusion created by society.

Due process

Fair procedures before a sanction: notice, a chance to respond, an impartial decision-maker and a right of appeal.

Distributive justice

Fairness in how scarce opportunities, resources, benefits and burdens are shared.

Definitions from the Ethics Cases glossary.

Discussion questions

1. Should the athlete or the governing body have to prove advantage?
2. Is height an appropriate measure of advantage for a runner on blades?
3. Was it fair to apply MASH before it was validated for Black athletes?
4. Does inclusion in open competition require a different standard from fairness?
5. What would a 'less-intrusive alternative' look like?

Sources

1. CAS partially upholds the appeal of Blake Leeper (media release) — Court of Arbitration for Sport
2. Court ruling barring 'blade runner' from Olympics is scientifically unfounded, studies suggest — CU Boulder Today
3. World Athletics panel decision on application from Blake Leeper — World Athletics
4. CAS dismisses the 2nd appeal of Blake Leeper (media release) — Court of Arbitration for Sport
5. Blake Leeper Response To Court Of Arbitration For Sport (CAS) Decision — Winston & Strawn via PR Newswire
6. Applicability of the prohibition of discrimination as part of public policy in relations between individuals – the Blake Leeper case — Sportlegis
7. Book C – C2.1 Technical Rules (in force from 1 November 2019) — World Athletics