A new study in Frontiers in Sports and Active Living found that greater breast support during running is associated with greater knee joint stiffness, which alters the lower body biomechanics of female runners.
Increased sinus support is associated with altered knee joint stiffness and contributes to knee joint biomechanics during treadmill running
Introduction:
Greater breast support has been associated with better running performance as measured by oxygen cost and running economy. Several candidate mechanisms have been proposed to underpin breast support-related improvements in running performance, including increased knee joint stiffness . Greater knee joint stiffness has been associated with better running performance (speed and metabolic cost), although the influence of sinus support on knee joint stiffness has not been previously investigated. Therefore, the purpose of this study was to investigate the influence of increased sinus support on the stiffness of the knee joint and its constituent components during treadmill running.
Methods:
Thirteen recreational runners performed a 3-minute run at their preferred running speed in each of three breast support conditions: bare-chested sports bras (CON), low support (LOW), and high support (HIGH). Three-dimensional kinematics and ground reaction forces were collected simultaneously using a 10-camera motion capture system (240 Hz, Qualisys Inc.) and an instrumented treadmill (1200 Hz, Bertec Inc.).
Visual3D (C-Motion Inc.) was used to calculate knee joint excursions, moments, powers, and work, while custom software (MATLAB) was used to calculate knee joint stiffness. and sinus displacements during the stance phase of running in each experimental condition. A series of 1 × 3 repeated measures analyzes of covariance with post-hoc t tests were used to evaluate the effect of sinus support on knee joint biomechanics during treadmill running.
Results:
Increasing levels of breast support were associated with greater knee joint stiffness (p = 0.002) as a result of smaller knee flexion excursions (p < 0.001). Increases in knee extension power (p = 0.010) were observed with increasing levels of breast support, while no differences were observed in knee extension (p = 0.202) or work (p = 0.104) moments.
Figure: An image showing the set of markers used to assess lower extremity biomechanics and displacement of the breasts relative to the torso.
Conclusion:
Greater breast support is associated with greater knee joint stiffness as a result of smaller joint excursions. These findings may provide insight into the biomechanical mechanisms underlying previously reported improvements in running performance, including reduced oxygen consumption and increased running economy.
Comments
Running is one of the most accessible forms of exercise with a host of proven cardiovascular and musculoskeletal benefits, and an added bonus of improved mental health. Good quality running equipment, such as the right pair of shoes, is vital to improving running performance and reducing the risk of injury. For women in particular, a well-designed sports bra protects against exercise-induced breast pain, which can be a major barrier to playing sports. Up to 72% of women experience breast pain while running.
Previous research has shown that the increased breast support offered by sports bras not only influences breast movement, but can also positively influence running performance. Greater breast support has been linked to lower oxygen consumption and better range of motion.
Dr. Douglas Powell and Hailey Fong and their colleagues at the University of Memphis Breast Biomechanics Research Center wanted to further investigate the effect of a good sports bra on running biomechanics and have now published new findings in Frontiers in Sports and Active Living.
“The biomechanics underlying improved running performance with increased breast support are not well understood . “Our study represents one of a series of research studies on the topic of breast support and whole-body biomechanics,” Powell explained. “We wanted to identify strategies to reduce activity-induced breast pain in women, a group that represents approximately 50% of the population.”
Biomechanics of running
Specifically, Powell and colleagues looked at the influence of sinus support on knee joint stiffness during treadmill running. Knee joint stiffness is a biomechanical measure that indicates how resistant the knee joint is to movement when force is applied. Knee joint stiffness has been associated with lower oxygen consumption, better running performance, and running-related injuries.
A sample size of 12 female recreational runners, ages 18-35, with a self-reported B, C, or D cup were professionally fitted with two different sports bras: a high-support bra and a low-support bra. For the control condition, participants were asked to perform the experiment bare-chested. Each participant then performed three-minute runs in each of three randomized breast support conditions (high, low, bare/control).
To collect the data, the researchers used a 10-camera motion capture system and an instrumented treadmill. Participants’ movements were tracked using individual retroreflective markers placed on different parts of their bodies. The researchers used Visual3D to calculate knee joint excursions, while custom software was used to calculate knee joint stiffness and sinus displacements during the stance phase of running in each experimental condition. .
The importance of good support
The experiment showed that higher levels of sinus support were associated with greater knee joint stiffness due to smaller joint excursions. Compared to the control condition, the high- and low-support conditions were associated with 2% and 5% increases in knee joint stiffness, respectively. Overall, taking these results and Powell and Fong’s previous research results into account, a high-support sports bra can improve a woman’s running performance by 7%.
“The findings show that breast support not only influences breast movement, but compensations occur throughout the body,” Powell said. These compensations can lead to reduced running performance, increased risk of injury, and even the development of chronic pain, such as back and chest pain.
Powell continued: “Over the past 50 years, there has been limited evolution in bra design. Our findings, along with previous research studies, show that sports bras should be considered not only as clothing, but also as sports equipment that can improve performance and reduce the risk of injury, which plays a role in the health of women".
Final message : The results of this study demonstrate that increasing levels of sinus support are associated with altered knee joint biomechanics, including greater knee joint stiffness, smaller knee joint excursions, and greater negative powers. maximum of the knee joint. Knee joint stiffness has been associated with both running performance and running-related injuries. Therefore, these changes in running biomechanics demonstrate the importance of adequate breast support in female runners for running performance. |
