A methodological proof-of-concept of the teeter-totter effect.
J Sports Sci
; 42(15): 1432-1438, 2024 Aug.
Article
in En
| MEDLINE
| ID: mdl-39207092
ABSTRACT
The Nike Vaporfly 4% (VP4) shoe is popular due to its unique design and reported performance benefits. However, the underlying mechanisms responsible for the improvements remain unclear. One proposed mechanism is the teeter-totter effect. This study aimed to 1) experimentally test the teeter-totter theory by estimating the teeter-totter moment (MTT) in the VP4 compared to a flat shoe (CONTROL) and 2) quantify the change in the anterior-posterior position of the centre of pressure (Δxa-p) in the VP4 compared to the CONTROL. Plantar pressures and high-speed video were recorded from 15 runners in two shoe conditions. The VP4 generated a larger propulsion moment, MP, (∫MPdt = 90.46 ± 38.87 Nms; p < 0.001, d = 1.95), suggesting the presence of an MTT in the VP4 (∫MTTdt = 57.16 ± 24.35 Nms) when compared to the CONTROL (∫MPdt = 33.30 ± 14.52 Nms). Δxa-p was greater in the VP4 (Δxa-p = 9.48 ± 6.08 mm; p < 0.001, d = 2.07) compared to the CONTROL (Δxa-p = 0.54 ± 0.67 mm). This study provides a methodological proof-of-concept for the teeter-totter theory. The findings highlight the possibility of a teeter-totter effect resulting in greater heel propulsion while running in an AFT shoe construction, assuming a constant muscle moment and pivot point.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Pressure
/
Running
/
Shoes
/
Equipment Design
/
Proof of Concept Study
Limits:
Adult
/
Female
/
Humans
/
Male
Language:
En
Journal:
J Sports Sci
Year:
2024
Document type:
Article
Affiliation country:
Canada
Country of publication:
United kingdom