Ключевые слова: anatomy, background, bending, biology, biomechanics, body, bone, calf, close, concept, dark, detail, educational, exercise, fitness, flexed, healthcare, human, illustration, joint, knee, leg, limb, medical, medicine, muscle, musculoskeletal, physiology, power, science, skeletal, strength, structure, study, system, tendon, textured, training,