This article is from WeChat public account: Nutshell (ID: Guokr42) , author: Generation day medicine, editor: Odette, from FIG title IC photo
A group of billowing penguins are swinging cheerfully on the ice, crackling! One fell down. Is the ice too slippery or the legs too short? Maybe because it eats too fat …
In order to study the relationship between fat and thin penguins and walking postures, scientists grabbed some penguins to walk on a treadmill, and then used half a month to lose weight and compare their posture changes. It was found that when the penguin was fat, it was easy to fall when walking, and it rocked more from side to side. [1] .
Someone said, is this a troublesome penguin? It ’s the same for feeding me fat on a treadmill, right? It really is. ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
图 丨 giphy
Fat, easy to fall
Sister or grandpaAs long as you are fat, you will fall more easily. “Fat” here does not mean weight, but excess fat. Muscle weight is also large, but “Zhuang” has a smaller effect on balance ability [2-4] .
The more the body fat percentage exceeds the standard, the easier it is to fall [5-7] . Moreover, it is possible to fall in all directions. After being fat, the risk of falling forward, falling backwards, and falling from left to right is all increased. This is because fat makes the whole process of adjusting balance more difficult, from finding the right position to adjusting the posture.
1, the pressure is too great, I can’t feel the change
It becomes difficult to find the center of gravity after gaining weight. It is difficult to maintain the center of gravity of the body when standing and walking, and it is easy to shake back and forth.
The position of the center of gravity is told by the plantar pressure and is sensitive to pressure. Only in this way can you find the deviation of the center of gravity in time, adjust the posture with muscles, and maintain balance. Weight gain weight, pressure on all parts of the foot is high, and it is no longer sensitive to pressure changes caused by the movement of the center of gravity. I ca n’t know exactly where I ’m at the center of gravity, so naturally it ’s difficult to put the center of gravity in the middle [8]
Fat people have high pressure on the soles of their feet, and their footprints are deep and wide 丨 pxfuel, pixnio
2, strength can’t keep up with weight
The body first calculates how to adjust the center of gravity based on the pressure of the feet, and then the muscles quickly and forcefully change their posture to stand. This requires muscle strengthMatch the weight to pull the body. Like a penguin, it eats round and round, but the muscles on its small legs are not growing, and it must be unstable.
After a person gains weight, although the legs also become thicker, the extent of muscle growth usually cannot keep up with fat, and the contraction efficiency decreases. Fat people often have absolute strength, but their relative weight is still not enough. (relative strength) is not enough to maintain balance while walking. [9, 10] .
3, there is more meat on the front, and the center of gravity moves forward
Muscles are attached to the bones. When contracting, the principle of leverage is used. When the resistance arm is extended, the muscles are more laborious to pull the body. (Junior high school physics teacher is watching you) .
When gaining weight, the belly is convex forward, and the extra meat on the front of the body is generally more than the back, and the center of gravity moves forward. Most of the muscle pivots that control the front-back balance are at the ankles. The forward movement of the center of gravity increases the distance from the pivots, the resistance arms are extended, and it is difficult for the muscles around the ankles to pull the body. = “Remarks”> [10] .
I can’t feel my feet, my muscles can’t move, and it’s really hard to maintain balance after gaining weight. In order not to fall, I had to change my walking posture.
Fat people have their center of gravity far from their ankles, and their arms are long (red line). References [11]
Different walking postures, but also more tiring
When a group of people walk together, you can see that everyone walks differently. The common characteristics of fat people are slow walking, short length of each step, large width between the feet, high arms, and straight legs. ( Hip and knee flexion angles are small) , thighs and buttocks are swung and turned more and more [9, 10] .
Walking is not simply hindered by thick legs. Mainly due to insufficient muscle strength, the body adjusts its posture to reduce energy expenditure, maintain balance and reduce joint pressure. [12-14] . Raising your arms, just like a penguin walks up, will raise its wings, in order to maintain balance, and reducing the pace and step length can reduce the knee impact.
The relative strength is originally small, and the posture has been changed for safety, reducing the efficiency of walking. It is indeed more tiring to walk after gaining weight.
Comparison of fat and thin walking posture 丨 Ian Green, Arakon N
The pressure is high and biased, and it may hurt your waist and legs
I usually do n’t like exercise after getting fat, because it is laborious, and because of the pain and discomfort that often occurs throughout the body. Studies have shown that fat people are more susceptible to muscle, ligament, joint, and bone damage than thin people, and they feel pain. Moreover, joint pain is not caused by old age. 60% of obese children have joint pain at least once a month. [14] .
I feel pain everywhere, mainly because the musculoskeletal is under too much stress. When walking, the whole body weight is pressed on the feet, and fat people are prone to foot pain. For every pound you gain, the pressure on the weight-bearing joints such as the knee joint increases by four pounds, so hip and knee pain are common. [14-16] .
After gaining weight, not only the musculoskeletal pressure is high, but also because of difficult posture control, abnormal spine curvature, knee valgus and hyperextension, and flat feet may occur. In these cases, the bones are not aligned properly, the pressure that should have been evenly distributed becomes concentrated, and the most stressed parts may be embarrassed and damaged. For example, knee valgus common in fat people (also known as X-shaped legs) Increasing pressure on the lateral cartilage of the knee joint may cause cartilage Causes irrecoverable damage [14] .
Fat people have a lot of joint stress, but the muscle strength around the joints that help reduce the stress is relatively weak, and the articular cartilage is forced to withstand more impact forces, which makes it more vulnerable to damage. [16, 17] .
The legs of normal size are basically on a straight line, and the angle of knee valgus becomes larger 丨 Reference [18]
Weight loss, but you can also regain your footsteps
Fatness causes so many problems. Can I return to normal after losing weight? Most can be improved, and the more fat you lose, the more obvious the effect.
However, if articular cartilage has already been damaged, full recovery is difficult. But joint pain can be alleviated, as long as the weight is reduced by 5%, the effect is more than 10%. [19] .
But when losing weight, if fat people copy the way of lean people, such as running and jumping every day, they may not be able to move their knees within a few days. If you are relatively heavy and rarely exercise, you can start with a form that does not carry weight. (such as cycling, do not take all the weight Press on the lower limbs) , and then gradually increase the weight-bearing exercise. Jumping movements are very stressful to the joints and can easily be injured. You need to be careful [20] .
In addition to the aerobic exercises commonly used in weight loss, it is best to add resistance exercises (strengthening training) . This will not only increase calorie expenditure, improve basal metabolism, help weight loss, but also strengthen muscle strength. Only when the relative strength is strong can joint pressure be reduced and the fatigue of daily activities can be reduced. [16] .
Finally, when you start exercising slowly, don’t fall down.
References
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[2] Meng H, O’Connor DP, Lee BC, et al. Alterations in over-ground walking patterns in obese and overweight adults. Gait Posture. 2017; 53: 145-150.
[3] Summa S, De Peppo F, Petrarca M, et al. Gait changes after weight loss on adolescent with severe obesity after sleeve gastrectomy. Surg Obes Relat Dis. 2019; 15 (3): 374-381.
[4] Meng H, O’Connor DP, Lee BC, et al. Effects of adiposity on postural control and cognition. Gait Posture. 2016; 43: 31-37.
[5] Teasdale N, Hue O, Marcotte J, et al. Reducing weight increases postural stability in obese and morbid obese men. Int J Obes (Lond). 2007; 31 (1): 153-160.
[6] Hue O, Simoneau M, MarcotteJ, et al. Body weight is a strong predictor of postural stability. Gait Posture. 2007; 26 (1): 32-38.
[7] H. Selçuk, N. Sermenli Aydın, H. Keklicek. The interaction of foot biomechanics and body mass index with single leg stance dynamic balance in healthy young. Gait Posture . 2018; 65: 315.
https://doi.org/10.1016/j.gaitpost.2018.06.202
[8] Villarrasa-Sapiña I, García-Massó X, Serra-Añó P, et al. Differences in intermittent postural control between normal-weight and obese children. Gait Posture. 2016; 49: 1-6.
[9] Cau N, Cimolin V, Galli M, et al. Center of pressure displacements during gait initiation in individuals with obesity. J Neuroeng Rehabil. 2014; 11: 82.
[10] Wearing SC, Hennig EM, Byrne NM, et al. The biomechanics of restricted movement in adult obesity. Obes Rev. 2006; 7 (1): 13-24 .
[11] Gallagher D, DeLegge M. Body composition (sarcopenia) in obese patients: implications for care in the intensive care unit. JPEN J Parenter Enteral Nutr. 2011; 35 ( 5 Suppl): 21S-8S.
[12] Rosso V, Agostini V, Takeda R, et al. Influence of BMI on Gait Characteristics of Young Adults: 3D Evaluation Using Inertial Sensors. Sensors (Basel). 2019 ; 19 (19).
[13] Lai PP, Leung AK, Li AN, et al. Three-dimensional gait analysis of obese adults. Clin Biomech (Bristol, Avon). 2008; 23 Suppl 1 : S2-6.
[14] Steinberg N, Nemet D, Pantanowitz M, et al. Gait Pattern, Impact to the Skeleton and Postural Balance in Overweight and Obese Children: A Review. Sports (Basel ). 2018; 6 (3).
[15] Messier SP, Gutekunst DJ, Davis C, et al. Weight loss reduces knee-joint loads in overweight and obese older adults with kne