Flat feet in adolescents are very harmful, early screening, early diagnosis and early treatment are the key!

Author: Pan Huajie, First People's Hospital, Shanghai Jiao Tong University School of Medicine

Reviewer: Yu Bo, Chief Physician, Shanghai First People's Hospital

Among Chinese adolescents, the proportion of patients with flat feet is as high as 25% to 49% [1]. In daily life, some parents may have heard their children say that their feet are uncomfortable and they feel pain from walking too much. Their children may even fall down when walking normally. Careful parents may also find that one side of their children's shoes is more worn out, which may be caused by flat feet.

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1. What are flat feet?

Flat feet can be divided into flexible flat feet and rigid flat feet. Flexible flat feet refers to the patient's arch being flat when under weight-bearing conditions and returning to normal when not under weight-bearing conditions, while rigid flat feet refers to the patient's arch being flat regardless of whether under weight-bearing or not [2].

Flexible flatfoot is an important category of flatfoot. Early flexible flatfoot is a physiological state. If it still cannot develop into a normal arch after the age of 6, it is a pathological state. If it is not intervened in time, it will cause great harm to the sports development and health of children and adolescents. Timely detection and intervention are the key to improving the prognosis of flexible flatfoot [3].

Normal foot: The sole of the foot is a natural arch.

Flat feet: The sole of the foot is basically flat.

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2. What are the dangers of flat feet?

The main manifestations are as follows:

1. Because the arch of the foot collapses and the cushioning is reduced, you will feel very tired or have foot pain after long-term exercise or walking;

2. Abnormal gait, with obvious pigeon toes turned outward or inward, prone to falling due to ankle and knee "fighting" while walking, poor balance, and affected movement;

3. Because it affects the force transmission of the arch of the foot, it causes the calf and thigh to rotate inward, leading to problems such as leg length difference, "X"-shaped legs, scoliosis, pelvic tilt, and uneven shoulders;

4. Pain in the hip, knee, ankle, lower back and back.

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3. How to conduct simple and effective assessment at home?

1. Observe the appearance: Observe whether there is a gap between the inner side of the foot and the ground. If there is no gap, it means the arch of the foot is collapsed;

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2. Measure the arch: Insert one finger under the inner arch, normally halfway to the front knuckle;

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3. Footprint analysis method [3]: barefoot, dip the sole of the foot in water or ink on white paper or dry, flat ground, or transparent glass to obtain a sole imprint;

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4. Three-line method: The tangent line of the inner edge of the arch is the first line, the line from the center of the third toe to the middle of the heel is the second line, the first and second lines intersect to form an angle, and the line dividing the angle equally is the third line. The three lines divide the footprint into the inner side, the middle side, and the outer side. The inner edge of the arch of a normal foot is on the outer side, the inner side of the arch of a mild and moderate flat foot is in the middle and inner side respectively, and the inner edge of the arch of a severe flat foot exceeds the inner side.

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5. Ratio method: draw a straight line from the most prominent part of the inner edge of the footprint to the baseline, take the midpoint of the inner concave edge of the footprint and draw a vertical line to the baseline, this vertical line and the baseline, the inner and outer edges of the footprint intersect at points a, b, and c (as shown in the figure), measure the distances ab and bc, and divide the arch of the footprint into 9 types according to the ratio of ab/bc. Type I (1:0) is an arched arch, type II (3:1), type III (2:1), and type IV (1.5:1) are normal arches, type V (1:1) is an intermediate type, type VI (1:1.5) is a mild flat foot, type VII (1:2) is a moderate flat foot, and type VIII (1:3) and type IX (0:1) are severe flat feet.

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4. What should I do if problems are found after the assessment?

The non-surgical treatment for flat feet is usually orthopedic treatment, which mainly customizes professional orthopedic insoles for flexible flat feet. Customized orthopedic insoles can well support the arch of the foot and maintain the stability of the arch of the foot[4]. However, orthopedic insoles require scientific and rigorous design and production by professionals to achieve reasonable support height and side protection to avoid excessive support and correction. At the same time, patients are also required to actively engage in sports training[5].

We can conduct the following training:

1. Upturned toes

Keep your feet on the ground and lift your toes as much as possible, feeling the instep tighten. Hold each movement for 3 to 5 seconds, 15 times per set, and practice 3 sets.

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2. Use your toes to pinch something

Use glass beads or towels between your toes to train the strength of your plantar muscles. Hold each movement for 3 to 5 seconds, 15 times per set, and practice 3 sets.

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3. Arch training

Keep your feet on the ground and arch your feet. Hold each movement for 3 to 5 seconds. Do 15 movements per set and practice 3 sets.

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4. Heel Raise Walking Training

Use your toes as support and walk forward slowly. This will improve your calf and foot muscle strength, increase body coordination, and improve your walking posture.

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5. Walking training

Walking barefoot on different hard and soft surfaces, such as grass, beach, cobblestone road, etc., can improve proprioception;

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6. Relaxation training of plantar muscles

Use a plantar fascia ball or stick to roll back and forth to relax the sole of the foot, relieve excessive tension and strain on the plantar muscles and fascia, and increase the flexibility of the plantar connective tissue. Roll for 2 to 3 minutes each time and repeat 3 to 5 times.

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7. Foot and calf stretching exercises

Use a towel, your hands, or step on a corner or inclined plane to increase the flexibility and extensibility of your toes and feet. Hold each stretch for 30 seconds and repeat 5 to 8 times.

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5. How to prevent flat feet?

Flexible flat feet can be detected and intervened early. According to the adverse factors that may cause flat feet, the following methods can be used to avoid their occurrence:

1. Parents should prevent their children from learning to walk too early during childhood;

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2. Avoid children from kneeling for long periods of time, such as sitting cross-legged or in a "W" shape;

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3. Control the child's weight to avoid being overweight and increasing the burden on the feet;

4. Prevent children from being exposed to activities such as skateboarding and roller skating too early;

5. When choosing shoes for children over 6 years old, you should choose shoes with good bottom support, just like adults.

References

Li Hai, Zhang Hairui, Zhang Hanyuan, et al. Research and progress of flat foot detection methods[J]. Chinese Journal of Health Standard Management, 2018, 9(9): 34-37.

[2] Dars Sindhrani, Uden Hayley, Banwell Helen A, et al. The efectiveness of non-surgical intervention (Foot Orthoses) for paediatric flexible pes planus: A systematic review: Update [J]. PLOS ONE, 2018, 13(2): e193060.

[3] Hui Junling, Chen Shujun, Xia Fengqi, et al. Comparison of flatfoot X-ray measurement method with ratio method and three-line method [J]. Journal of Anatomy, 2007, 30(2): 232-234.

[4] Zhou Xiangying, Zeng Qing, Liao Zhengwen, et al. Application of customized orthotic insoles in the treatment of flat feet[J]. Chinese Journal of Tissue Engineering Research, 2022, 26(28): 4587-4592.

[5] Zhang Jin, Jiang Shuyun, Li Yang, et al. Research progress in diagnosis and prevention of flexible flat feet in children[J]. Chinese Journal of School Health, 2023, 44(6): 946-950.