yogabook / pathologie / muscular imbalances of the leg muscles

Muscular imbalances in the leg muscles, consequences in the pelvis and upper body

Definition of

Imbalance of strength, tone and flexibility of the agonists and antagonists in the hip joint

Cause

1. one-sided stress in the figurative and literal sense in sport or everyday life
2. Incorrect execution of movements in sport or everyday life
3. Lack of exercise, stress or training
4. Injuries and their consequences
5. Disorders of the innervation

Diagnosis

1. Inspection
2. Surveying
3. Muscle tests

Symptoms

1. with weak extensors of the hip (ischiocrurals and gluteals): the relatively stronger hip flexors tilt the pelvis forward, resulting in a forward shift of the center of gravity, which is usually followed by a backward shift of the upper body and (following the minimal muscle tension) tilting of the pelvis into slight extension, where it remains due to the lig. Iliofemoralia and the hip flexors. The effort to keep the head upright leads to hyperkyphosis in view of the posteriorly tilted lumbar spine and lower thoracic spine.
2. If the flexors of the hip are shortened: the pelvis tilts forward into flexion in the hip joint, the upper body’s centre of gravity is in front of the acetabuli, which is why the lumbar spine is hyperlordized, the knees are slightly flexed and the OSGs are in slight dorsiflexion. If the shortening is unilateral, the pelvis is twisted, the shortened side tilts forward and is lower on average. This is followed by scoliosis, affecting the SI joint, the vertebral joints of the lumbar spine and possibly also the thoracic and cervical spine, as well as an apparent (functional) difference in leg length. Another consequence is a rocking gait with alternating sideways bending and straightening of the upper body.
3. Shortening of the abductors or adductors: displacement of the pelvis in the frontal plane, uneven and therefore one-sided overloading of the SI joints, depending on the severity, functional leg length discrepancies (shortening of the abductors: ipsilateral lengthening of the leg, shortening of the adductors: ipsilateral shortening of the leg), one knee is bent to compensate and the leg is slightly abducted contralaterally. The result is a consecutive scoliosis.
4. If the abductors are weak: Statically when standing on one leg and kinetically during walking, for example, only the abductors stabilize the pelvis in the frontal plane against lateral sinking. Minor weakness of the abductors leads to the unsupported side of the pelvis sinking(Trendelenburg sign), bilateral weakness therefore leads to the manequilibrium. If the weakness is more pronounced, the partial body weight (body weight minus supporting leg) is shifted over the hip joint to relieve the abductors, resulting in a waddling gait(Duchenne’s sign)
5. in the case of weakness of the quadriceps: in the case of only slight flexion, the center of gravity of the upper body is already behind the axis of movement of the knees and the quadriceps must work. In the case of hyperextension, the plumb line would be in front of the axis of movement and the dorsal ligaments and the capsule would stabilize the joint without muscular involvement. To relieve the quadriceps in the event of weakness, the pelvis can be tilted forward with the upper body. Statically, the knee can then be extended and remain extended effortlessly; dynamically, walking is facilitated and the hyperextension of the knee is increased.
6. if the hamstrings is weak: With the exception of the biceps femoris caput breve, the hamstrings is biarticular: knee-selecting and hip-extending. In standing and moderate walking, the ischiocrural group are the main extensors of the hip; the glutes only become active under greater flexion and load. A weakness of the hamstrings causes the pelvis to tilt forward into flexion and the knee to fall too easily into hyperextension when standing. Although these are the antagonists, the clinical picture is similar to that of weakness of the quadriceps, except that in the latter case the pelvis is actively tilted forward to relieve the quadriceps; in the case of weakness of the hamstrings, it tilts forward from the pull of the hip flexors. Here too, the gait is characterized by increased hyperextension.
7. if the triceps surae is shortened: this results in increased dorsiflexion in the ankle joint and increased supination in the ankle joint(pointed foot) with an apparent lengthening of the leg, which is compensated for by slight flexion in the knee joint. When walking, the forefoot is placed on the ground first and flexion in the knee remains greater than normal. If the affected leg is pulled forward from behind, more flexion is required in the hip to prevent the forefoot from hitting the ground
8. if the foot lifts are weak: when walking, the rear forefoot, which is to be pulled forward, would drag briefly on the ground, which is why more flexion is required in the hip. If the foot is placed in front, the forefoot reaches the ground first, resulting in a stepper or stork gait.

Complications

1. See the corresponding images: scoliosis, hyperkyphosis of the thoracic spine, hyperlordosis of the lumbar spine,…

Therapy

1. Elimination of muscular imbalances
2. KG
3. Exercise training