Kinetisense Newsletter

The single leg balance test assesses multiple aspects of the patient’s/client’s functional abilities. Approximately 85% of the normal gait cycle involves standing on one leg (1). This test challenges the motor control and balance of a patient, as well as their kinesthetic awareness. This is particularly relevant for the elderly population, as proprioception, balance, and coordination typically diminish with age.

Research has found that patients that report sacroiliac (SI) joint pain during a single leg stance have delayed firing of muscles on the symptomatic side, specifically the internal obliques, multifidi, and gluteus maximus (2). The biceps femoris on the other hand was found to be activated much sooner (2). EMG testing revealed that the muscle firing patterns on the symptomatic side differed significantly from the asymptomatic side. It was discovered that the delayed firing of the multifidi and internal obliques decreased their ability to serve as stabilizing muscles at the lumbopelvic region (2). It was also found that the early activation of the biceps femoris may be present due to a compensation for a delay in the firing of the gluteus maximus, which is responsible for extension at the hip and force closure of the SI joint via the sacrotuberous ligament and thoracolumbar fascia (2, 3). Other research has shown that poor balance may be associated with low back pain. One study in particular looked at excessive anterior and posterior sway during a single leg balance test and correlated this to the presence of low back pain (4). A similar study also noted that a deficit in balance abilities is correlated to an increased risk of developing low back pain (5)

From a performance standpoint, vestibular balance is a key assessment in regards to functional movement. Balance and its associated patterns of movement give insight into core, pelvic, and trunk stability, as well as strategies that are employed to establish or maintain a centrated center of mass (COM). The pelvis is the keystone for the entire body, with many of the myofascial slings passing through this area. Poor balance is often an indicator of the lack of stability and strength of the posterior chain, specifically the gluteus medius, gluteus maximus, hamstrings, gastrocs, and soleus muscles. The vestibular system also plays a key role in coordinating both basic and advanced movements. This system provides important information to the central nervous system regarding the spatial positioning of the body. The proper integration of vestibular and visual afferent input provides the foundational information that is required for the efferent activation of the core and non-core muscles. Performance in a sport often requires stability, mobility, explosive strength, coordination, and speed. The ability to efficiently process spatial information is required so that these other efferent processes can occur. Given its importance, the vestibular system should be trained through balance and proprioceptive training in order to optimize performance.