Functional Anatomy of the Female Pelvic Floor

The anatomic structures in the female that prevent incontinence and genital organ prolapse on increases in abdominal pressure during daily activities include sphincteric and supportive systems. In the urethra, the action of the vesical neck and urethral sphincteric mechanisms maintains urethral closure pressure above bladder pressure. Decreases in the number of striated muscle fibers of the sphincter occur with age and parity. A supportive hammock under the urethra and vesical neck provides a firm backstop against which the urethra is compressed during increases in abdominal pressure to maintain urethral closure pressures above the rapidly increasing bladder pressure. This supporting layer consists of the anterior vaginal wall and the connective tissue that attaches it to the pelvic bones through the pubovaginal portion of the levator ani muscle, and the uterosacral and cardinal ligaments comprising the tendinous arch of the pelvic fascia. At rest the levator ani maintains closure of the urogenital hiatus. They are additionally recruited to maintain hiatal closure in the face of inertial loads related to visceral accelerations as well as abdominal pressurization in daily activities involving recruitment of the abdominal wall musculature and diaphragm. Vaginal birth is associated with an increased risk of levator ani defects, as well as genital organ prolapse and urinary incontinence. Computer models indicate that vaginal birth places the levator ani under tissue stretch ratios of up to 3.3 and the pudendal nerve under strains of up to 33%, respectively. Research is needed to better identify the pathomechanics of these conditions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72597/1/annals.1389.034.pd

Fall risk in an active elderly population – can it be assessed?

BACKGROUND: Falls amongst elderly people are often associated with fractures. Training of balance and physical performance can reduce fall risk; however, it remains a challenge to identify individuals at increased risk of falling to whom this training should be offered. It is believed that fall risk can be assessed by testing balance performance. In this study a test battery of physiological parameters related to balance and falls was designed to address fall risk in a community dwelling elderly population. RESULTS: Ninety-four elderly males and females between 70 and 80 years of age were included in a one year follow-up study. A fall incidence of 15% was reported. The test battery scores were not different between the fallers and non-fallers. Test scores were, however, related to self-reported health. In spite of inclusion of dynamic tests, the test battery had low fall prediction rates, with a sensitivity and specificity of 50% and 43% respectively. CONCLUSION: Individuals with poor balance were identified but falls were not predicted by this test battery. Physiological balance characteristics can apparently not be used in isolation as adequate indicators of fall risk in this population of community dwelling elderly. Falling is a complex phenomenon of multifactorial origin. The crucial factor in relation to fall risk is the redundancy of balance capacity against the balance demands of the individuals levels of fall-risky lifestyle and behavior. This calls for an approach to fall risk assessment in which the physiological performance is evaluated in relation to the activity profile of the individual

Spasticity

Antispastic medications that are directed to reduce clinical signs of spasticity, such as exaggerated reflexes and muscle tone, do not improve the movement disorder. Medication can even increase weakness which might interfere with functional movements, such as walking. In this chapter we address how spasticity affects mobility and how this should be taken into account in the treatment of spasticity. In clinical practice, signs of exaggerated tendon tap reflexes associated with muscle hypertonia are the consequence of spinal cord injury (SCI). They are generally thought to be responsible for spastic movement disorders. Most antispastic treatments are, therefore, directed at the reduction of reflex activity. In recent years, a discrepancy between spasticity as measured in the clinic and functional spastic movement disorder was noticed, which is primarily due to the different roles of reflexes in passive and active states, respectively. We now know that central motor lesions are associated with loss of supraspinal drive and defective use of afferent input with impaired behavior of short-latency and long-latency reflexes. These changes lead to paresis and maladaptation of the movement pattern. Secondary changes in mechanical muscle fiber, collagen tissue, and tendon properties (e.g., loss of sarcomeres, subclinical contractures) result in spastic muscle tone, which in part compensates for paresis and allows functional movements on a simpler level of organization. Antispastic drugs should primarily be applied in complete SCI. In mobile patients they can accentuate paresis and therefore should be applied with caution

Soleus Stretch Reflex Inhibition in the Early Swing Phase of Gait Using Deep Peroneal Nerve Stimulation in Spastic Stroke Participants

Objectives: To investigate the feasibility of inhibiting the stretch reflex of the soleus muscle by a conditioning stimulus applied to the deep peroneal nerve in spastic stroke participants during the early swing phase of gait. - Materials and Methods: This study investigated the effect of an electrical conditioning stimulus applied to the deep peroneal nerve on the magnitude at the peak of the soleus stretch reflex in the early swing phase of gait in six spastic stroke participants. - Results: Five of the six participants showed a reduced stretch reflex of more than 80%. On average (n= 4), it was shown that maximal inhibition occurred at a conditioning-test interval of 114 ms and had a magnitude of more than 90% (p < 0.05). For all five participants investigated, there was a significant reduction in the sensitivity of the soleus stretch reflex after conditioning (p < 0.02). - Conclusions: It is concluded that the inhibition of the soleus stretch reflex with an electrical conditioning stimulus applied to the deep peroneal nerve is feasible in the early swing phase of walking. This shows a potential for being used in the rehabilitation of walking by spastic stroke persons