Physical Fatigue Affects Gait Characteristics in Older Persons Ⅱ

DISCUSSION

We have investigated how physical fatigue influences gait, and have found changes in gait characteristics at trunk and foot level, but no changes in gait speed in an FG relative to a CG. The increased step width and ML trunk acceleration amplitude in the FG participants following fatigue indicates that participants adopted a broader base of support and 

a concomitant increase in lateral weight shift. Interestingly, ML step-width variability and ML interstride trunk acceleration variability did not show any signifificant Time * Group interactions, supporting previous findings that increased ML excursions may not be accompanied by larger ML variability when capacity for balance control is challenged in older persons (25).

 Anti-fatigue health supplement for older people

 Trunk movements in the line of progression can be decomposed to the AP and V directions. In our study, AP and V acceleration amplitudes were not affected by the fatiguing task for the FG as a whole. At the foot level, this was also the case for step length. Lack of change in the AP and V accelerations may explain why gait speed did not differ between groups at posttest. The same phenomenon

Figure 3. Pretest–posttest changes in anteroposterior (n), vertical, and mediolateral (r) trunk acceleration root mean square with 95% confidence interval for the control group and the fatigue group. was observed by Kavanagh and colleagues (16) in young healthy persons following fatigue. However, for variability measures in the direction of progression, results indicate larger variability for the FG at posttest. So even if mean

measures of progression were not affected, but the consistency of progression was. A shift in walking strategy without a change in gait speed might be understood as an attempt to keep a constant or optimal output but at the price of a higher cost of compensation (26). It is thus reasonable to suggest that this shift in movement strategy may increase the risk of balance loss during walking. The increase in step-length variability in the FG may be explained by fatigue in muscles controlling movements in the sagittal plane and is in line with earlier studies that found step-length variability to distinguish between older persons with and without risk of falling (19,20,27). 

A higher interstride trunk acceleration variability in the AP and V directions and lower in the ML direction in frail persons compared with fifit older persons has been reported earlier (21). The findings in the present study suggest that, after being fatigued, the older individuals adopted gait characteristics resembling those of frail persons. The opposing patterns of change for ML versus V and AP variability is interesting because increased variability often is regarded as a general sign of decreased gait control (19,28–30). However, our findings are supported by those of some earlier studies (16,21), and they indicate that variability in ML trunk movements may be necessary for effectively controlling the center of mass during walking. Unlike most muscle fatigue studies, in our study individual load during fatigue was not graded relative to each participant’s maximal capacity, possibly resulting in an increased range in the number of sit-to-stand trials between participants. 

The highly signifificant decrease in sit-to-stand velocity from the first five to the last five trials and larger fatigability found in those participants with the fewest repetitions also indicate that participants who performed few repetitions were fatigued. However, we cannot conclude whether fatigue was caused by muscle fatigue or fatigue in other body systems (e.g., the lungs or the circulatory system). We found an overall increase in gait speed from pre- to posttest that could possibly explain changes in gait characteristics. However, we have controlled for the effect of gait speed on all gait variables and found that the increase in gait speed was the same for the FG and the CG, thus strengthening our findings that the changes in gait characteristics in the FG from pre- to the posttest are likely to be a result of a change in movement strategy and not due to increased gait speed. This study has some limitations. We did not randomize participants to the FG and CG. However, baseline gait characteristics demonstrated no signifificant group differences. At posttest, the CG walked back and forth at a slow speed before the two counting trials at the preferred speed. 

Thus, this study cannot answer whether these two slow walks may have affected gait characteristics at posttest for the CG. We have also used more than one gait outcome parameter, which may have increased the risk of false-positive findings. To our knowledge, this is one of the first studies to assess the effect of physical fatigue on gait and the first study to investigate how fatigue through a physical everyday activity affects gait control. We have demonstrated changes in gait control following physical fatigue, even if gait speed did not change. For the sample as a whole, the changes were in the direction of what frail older persons and persons at risk of falling are demonstrating, even if changes in trunk acceleration RMS varied between participants in the FG. More studies on physical fatigue in older persons should be performed, using complex motor tasks of relevance to daily life.

FIND THE BEST NATURE SUPPLEMENT TO REDUCE FATIGUE

Our carefully hand-crafted Neuro Regen formula includes the best-researched herbs. Each shows amazing potential for relieving fatigue management.

Includes:

Cistanche-

① Cistanche contains a variety of polyphenols and glycosides, which can increase the activity of antioxidant enzymes and have the function of eliminating free radicals;

③ Cistanche has the function of nourishing the kidney and strengthening yang, and can improve the hypothalamus-pituitary-hypophysis caused by heavy exercise The function of the gonadal axis promotes the secretion of testosterone, is beneficial to the body's anabolism, and has anti-fatigue effects; 

④ Cistanche contains a variety of effective ingredients, which can promote the body's energy metabolism and play an anti-fatigue effect.