At The Injury Clinic, we often talk about running efficiency and running related injuries. It can be difficult to link running efficiency and running related injuries with breasts and bras; but recent research has identified several key factors that contribute to running related injuries which can be modified by wearing a supportive sports bra.
A FEW FUN FACTS…
- Breasts reported as a barrier in:
- 1 : 5 adults, and
- 1 : 2 adolescents.
- Up to 72% of women experience exercise induced breast pain and report it is a significant barrier to exercise.
- 32% of women running the London Marathon reported pain, and also reported doing nothing about it.
- If you run 10km in an hour, your breasts will bounce ~10,000 times (which is significant!).
***BUT***
85% of women are wearing ill-fitting bras, and 60% of elite athletes have never been fitted with a sports bra.
WHY IS THIS IMPORTANT?
When we look at the statistics around breast pain with activity, it is important as breast pain can often be modified yet many women haven’t considered different strategies to manage their symptoms.
We know that when you wear a highly supportive sports bra, all planes of breast movement will be reduced. This is important as during running, a D-cup breast can experience up to 20cm of vertical displacement and vertical velocities of 80-100cm/s. If we then think that this will be happening 10,000 times in a 10km run, it’s no wonder so many women experience breast pain while running!
It is also important to note that repeated load secondary to excess movement will lead to irreparable damage to supporting structures. The skin will resist strain up to 30%, but irreversible damage happens at 60% strain. So essentially, if there is excessive breast movement while running, it is possible that irreversible change will occur to the breast tissue.
WHAT CAN BE DONE?
Wearing a highly supportive sports bra is the best thing that can be done to moderate and manage breast pain during activity. Not only does increasing support reduce all planes of breast movement, it also alters running kinematics and bioenergies.
CAN A GOOD SPORTS BRA DO MORE THAN MODIFY PAIN?
While pain is an important consideration, it is also interesting to note that when wearing a highly supportive sports bra (vs low support) there was a 7% reduction in oxygen consumption, and improved running economy while other running characteristics (cadence, step length and ground contact time) were unchanged.
Biomechanically, it is thought that the following factors improve running performance;
- Altered transverse plane trunk and pelvis kinematics, and,
- Increased lower extremity stiffness
→ So increased breast support increases peak trunk and pelvis rotations as well as greater trunk and pelvis ranges of motion.
Researchers also noted that higher breast support was associated with:
- Greater cadence,
- Reduced stride time,
- Reduced stride length,
- Greater knee stiffness,
- Greater peak negative knee joint powers, and
- Smaller knee joint excursions.
We know that when we are running, increased knee joint stiffness is associated with improved running performance, which includes reduced oxygen consumption and improved running economy. A highly supportive sports bra will improve knee joint stiffness by up to 5%!
So essentially, when wearing a supportive bra, breast velocities reduce, breast pain and injury risk reduce, and women are able to run with the most metabolically advantageous movement strategy. It is also important to note, the bigger the breast size, the greater difference a sports bra will make to these numbers.
BRAS & ACL INJURIES?
Recent research has also indicated that varying levels of breast support will change knee mechanics so drastically that the likelihood of ACL injuries can be affected. Researchers discovered that when landing from a jump, women had greater knee and trunk flexion and less knee valgus angles. The combination of these factors improves neuromuscular control of the knee, therefore reducing the risk of ACL injuries.
IN SUMMARY…
Having a supportive sports bra that fits properly is important! In running populations, it will improve efficiency and reduce running related injuries. In those who play cutting sports, a supportive sports bra has the potential to reduce the likelihood of ACL injuries.
It is also important to note, having a professionally fitted everyday bra is important. Breasts can have a direct impact on neck, shoulder and back pain, and this pain can often be modified by a well fitting everyday bra. For more information, please contact us via phone (03 5229 3911) or email (info@theinjuryclinic.com.au), or click here to book an appointment with one of our physios online.
