The core is the building block of stability and serves as the foundation for any movement. Core stability is defined as the ability to control the position and motion of the trunk over the pelvis to allow optimum production, transfer and control of force to the extremities. Specific to tennis, 54% of the force generated in the serve comes from trunk and lower extremities; this gives testament to the core often being referred to as the “powerhouse.”
Visualize the core as a cube. The front wall is the transverse abdominis (anterior abdominals), the back wall the spinal erectors (muscles along the spine), the sides are composed of the internal and external obliques, the top/roof the diaphragm (a muscle responsible for expanding the rib cage when you inhale), and the bottom/foundation is the pelvic floor. The transverse abdominis is unique in that this muscle fires in anticipation of movement helping to create increased stiffness of the lumbar spine. Simultaneous contraction of the diaphragm, the pelvic floor muscles, and the abdominal muscles is required to increase intra-abdominal pressure, providing a more rigid cylinder for trunk support, decreasing the load on the spine muscles and allowing increased trunk stability. ALL muscles must work in synchrony to avoid dysfunction and possible injury. If one area of the cube is malfunctioning, it weakens the entire system, leaving the body susceptible to considerable stress. Let’s learn more about one part of the cube that is often forgotten, the pelvic floor.
Your pelvic floor muscles are an important group of muscles in your internal pelvic area, and as stated above, play a crucial role in providing trunk and core stability. They are attached to the pubic bones at the front, the coccyx (tail) bone at the back and the lower internal rim of the pelvic bones. When functioning properly, they provide support against gravity for your pelvic organs (bladder, uterus and bowel).
The pelvic floor assists with:
To function normally, the pelvic floor needs to be able to both contract to maintain continence and to relax for voiding. All muscles, including those of the pelvic floor, function best at their ideal resting length. If a muscle is too tight (shortened) or over stretched (lengthened) the activation pattern and subsequent action will be alerted. The pelvic floor muscles, like any other muscles in the body require strength, flexibility, and endurance to function well.
Pelvic Floor Dysfunction (PFD) is any condition or impairment of muscle, nerve, or fascia that limits normal pelvic floor function, including proper bowel and bladder function, lumbopelvic stability, and sexual function. It can include:
The pelvic floor muscles can be weak due to chronic increased tightness or ligament laxity. Exercise prescription must be individualized and depends upon objective measures gathered by a medical provider. Kegel exercises (tightening of the pelvic floor), although beneficial, may not be appropriate for everyone, especially for those with hypertonic (tight) pelvic floor muscles. Tension/tone of the pelvic floor muscles can be diagnosed by a specialist pelvic floor physical therapist. See your primary care physician for a referral to a pelvic floor physical therapist.
Research indicates that individuals with low back pain have a significant decrease in pelvic floor function compared to individuals without low back pain. Compensatory patterns seen in the pelvic floor can originate from the low back, sacrum, hip, knee and ankle. With treatment of the musculoskeletal system, improving awareness and control of the pelvic floor muscles must be considered, and for the pelvic floor to function well, muscles of the pelvis and lower extremities must be balanced. Of the thirty muscles that attach to the pelvis, 23 connect the legs and pelvis. Muscle imbalance and abnormalities in anatomical alignment, particularly at the pelvis, will compromise lumbopelvic stability, as well as hip and knee function. For example, weakness of the hip abductors and hip external rotators can result in greater hip adduction and femoral internal rotation, which can contribute to increased knee valgus and thus possibly result in patellofemoral injury. Muscle imbalance of the legs and trunk musculature can also lead to injury including chronic hamstring strain, groin pain, and low back dysfunction. Addressing proper alignment and muscle balance are essential components of rehabilitation as this improves movement efficiency, prevents injury, and enhances overall performance.
A key muscle for proper pelvic floor and hip muscle function is the obturator internus (OI). This muscle helps maintain position of the thigh bone (femur) in the hip socket (acetabulum) and functions to externally rotate the hip. Muscle action at the OI can affect pelvic floor muscle tension. Dysfunction at the OI and hip can contribute to musculoskeletal dysfunction such as low back pain, sacroiliac dysfunction, hip labral compromise, other issues affecting lower extremity kinetic chain and PFM dysfunction including, incontinence, pelvic organ prolapse, and pelvic pain.
As you can imagine, movement of the extremities without core control and stability alters the loading pattern of the spine and often leads to low back pain, hip pain, and other various injuries. Proper lumbopelvic stability is imperative to create a stable base for the extremities to move on during dynamic movement. With this understanding of the relationship between the hips, low back and pelvis, you can see that a training program should start with exercises that isolate specific core muscles but must also progress to include complex movements and incorporate other training principles such as proper power development.
Muscular imbalance of the walls of the cube (core) can lead to compensatory movement patterns, inefficient energy dispersion, and possible microtrauma to soft tissue. For example, an unstable pelvic floor can alter diaphragm and rib cage function, therefore affecting shoulder mechanics. When abdominal muscle strength is out of proportion to pelvic floor muscle strength, the support function of the pelvic floor muscles can be compromised leading to prolapse of pelvic organs, pain or incontinence. To achieve balance, core stability training must include exercises addressing the multifidi, transverse abdominus, pelvic floor and diaphragm muscles in multiple positions. As stated above, you must then integrate singular muscle activation into general movement patterns because the muscles of the core work in synchrony and as a unit. This includes the muscles of the lower extremity: the glute medius, minimus and hip rotators. Core stability practice including exercises and drills to improve the hip, knee, ankle/foot alignment is also essential. The appropriate position of the joints and muscles allows normalized neural input and appropriate muscle length-tension relation to facilitate the synchrony of the core muscles to stabilize in functional movement patterns. See a pelvic floor physical therapist to receive an exercise program designed to improve your core.
Pilates is exercise that focuses on whole body integration to improve movement through enhanced posture, alignment, flexibility, strength, and stability. It can be performed using the unique Pilates equipment or in a traditional mat Pilates format. In both forms, Pilates utilizes breathing to help facilitate proper movement patterns and improve core stability. Pilates is a great tool to build foundational strength, stability, and motor control needed for overall athletic performance.
Single Leg Femur Arcs
**Check in with your alignment throughout the exercise. Did your hips rock from side to side? Is there more of an arch in your back than when you started? Be sure to self-correct throughout!
The information provided within this Physically Speaking topic is for informational purposes only and should not be treated as medical, psychiatric, psychological, health care or health management advice. If you have any health or related questions or concerns, please consult your physician or other qualified health care professional.
A special thank you to our author, WTA Primary Healthcare Provider and owner of Restore Motion, Reshma Rathod, MSPT, MBA