Prolonged negative emotions may lead to a host of problems for people, including phobias and anxiety disorders, depression, and a number of stress-related physical disorders [Fredrickson].
Depression has been shown to be an independent risk factor for falls [Stalenhoef]. It is associated with a characteristic pattern of cognitive deficits, affecting mainly attention, executive function, and processing speed. In older adults, walking becomes more of a cognitive task and less automatic. They need to allocate greater attention to walking to compensate for changes in their sensory and motor function. When walking with distractions, depressive symptoms and deficits in executive function are associated with increased unsteadiness [Hausdorff 2008]. People with depression have also been shown to demonstrate an altered gait pattern characterized by reduced walking speeds, vertical head movements, and arm swinging, shorter stride length, longer standing phase, and increased gait variability [Michalak; Hausdorff 2004]. These gait features have been shown to be linked to an increase risk of falling [Hausdorff 2001; Maki]. People with increased sadness and depression also display larger lateral swaying movements of the upper body and a more slumped posture, which may displace the center of gravity and make someone more prone to balance problems and falls.
Fear and anxiety have also been linked to an increase risk for falls [Lavedán; Hallford]. A healthy fear of falling may make someone more cautious and aware of their environment and surroundings. Most studies report a prevalence of a fear of falling at 25-50% in community-dwelling seniors. However, approximately half of those who are fearful develop an unreasonable or extreme fear of falling and will begin to withdraw or avoid activities such as socialization, hobbies or recreational activities, or leaving their home altogether [Murphy]. An unreasonable fear of falling is also a risk factor for future falls [Lavedán]. Older adults who are fearful of falling also walk with abnormal characteristics, which may in fact increase their risk for falling [Menz]. They tend to walk more slowly, take shorter strides, have a wider base, and have a longer double limb support time and increased variation in their gait [Chamberlin]. Many often walk with slumped posture and their head looking down, which may displace their center of gravity and also limit their ability to observe potential obstacles in their environment. When attempting to make postural corrections for balance, they often make disproportionate adjustments and display increased stiffness [Delbaere; Nagai]. Similar gait characteristics have been observed in those with increased anxiety [Pluess; Richards]. It has been shown that older adults may have an increased risk for a fall with a serious injury, including hip fractures, for up to one hour after a perceived stressful event (anger, worry, sadness, anxiety, fear) [Stalenhoef].
The practices of tai chi and qigong have been shown to have positive effects on emotional well-being in both young and old adults [Zhang]. It has been suggested that these practices reduce negative emotions by enhancing attentional control, improving emotion regulation and altering self-awareness during the meditative movements [Tang]. Tai chi and qigong have been shown to induce physical changes and enhanced functional connectivity in various regions of the brain among practitioners [Wei; Tao]. These physical changes and improved connections have coincided with improvements in mood or emotional states.
Meditation which is an integral part of tai chi and qigong has been reported to improve symptoms of depression and anxiety through the modulation of functional connectivity between the dorsal anterior cingulate cortex and insular cortex [Yang]. The medial prefrontal cortex has been linked to increasing our attention to positive, pleasant emotions and suppressing negative emotions such as sadness or depression [Critchley]. Along with the anterior cingulate cortex, the medial prefrontal cortex is also involved in emotional processing, namely in fear and anxiety. They both also work together to process fear memory and emotional conflict [Etkin]. Additionally, connections between the medial prefrontal cortex and bilateral hippocampus have been shown to be increased in tai chi practitioners [Tao]. As stated earlier, the medial prefrontal cortex is involved in the regulation of memory, while hippocampus is involved in regulation of both memory and emotion. This enhanced connection may improve emotional processing by linking up the current emotion with previous events [Yu].
The thalamus, ventral hippocampus, and right inferior segment of the circular sulcus of insula were shown to have larger gray matter volume in those who practiced tai chi compared to those who did not. This increase in size also correlated to significant improvements in emotional processing and stability, and these areas have also been linked to modulating anxiety. [Liu; Wei]. Another part of the brain, the amygdala, has also demonstrated changes in structure and connectivity after meditation practices. The amygdala has a crucial role in regulating stress and associated responses. Under stressful conditions, the amygdala has demonstrated increased functional activity with various regions of the brain [Hölzel]. However, after mindful meditation, research has shown that not only does the volume of the amygdala decrease, but the activity of the amygdala decreases as well, which has correlated to decreased reports of stress and anxiety in individuals [Taren].
Studies of tai chi practitioners also reveal increased gray matter density in the right insula compared to that of members of a control group. The insula is believed to be responsible for integrating internal and external information and for forming a global perception of how the self feels, or interoception [Craig]. It is also believed to generate emotionally relevant contexts, such as emotional pain, happiness and sadness [Critchley]. Many psychological disorders such as depression and anxiety involve problems with the perception of the body and the emotions produced by various interoceptive signals [Paulus]. These problems may be related to structural
declines/atrophy in the insula [Soriano-Mas]. The resultant increase in gray matter of the insula in tai chi practitioners may also help to explain the alleviation of symptoms, and experience of peacefulness and relaxation during tai chi practice [Wei].
Overall, the improvements in gray matter density and improved functional connections among these regions of the brain may help explain the improvement in emotions and mood related symptoms among tai chi and qigong practitioners, thus decreasing significant risk factors for falls in the elderly.