Crouch Gait in Cerebral Palsy: Current Concepts Review

Abstract

Background and objective: Crouch gait is the most common pathological gait pattern in cerebral palsy and is commonly seen in patients with spastic diplegia. It is characterized by excessive knee flexion throughout the stance phase of gait cycle. The aim of this review is to discuss the current literature about CG for a more comprehensive understanding.

Methods: A literature review about various aspects of crouch gait in cerebral palsy was undertaken. This included its etiology and pathophysiology, biomechanics in crouch gait, natural history of untreated crouch gait, clinical and radiological evaluation and different modalities of available treatment.

Results: The etiology is multifactorial and the pathophysiology is poorly understood. This makes its management challenging, thereby leading to a variety of available treatment modalities. Inadvertent lengthening of muscle-tendon units is an important cause and can be avoided. A meticulous clinical and radiological evaluation of patients, supplemented by observational and instrumented gait analysis is mandatory in choosing correct treatment modality and improving the treatment outcome. Younger children can be managed satisfactorily by various non-operative methods and spasticity reduction measures. However, crouch gait in cerebral palsy has a progressive natural history and surgical interventions are needed frequently. The current literature supports combination of various soft tissue and bony procedures as a part of single event multilevel surgery. Growth modulation in the form of anterior distal femur hemiepiphysiodesis for correction of fixed flexion deformity of knee has shown encouraging results and can be an alternative in younger children with sufficient growth remaining.

Conclusions: In spite of extensive research in this field, the current understanding about crouch gait has many knowledge gaps. Further studies about the etiopathogenesis and biomechanics of crouch using instrumented gait analysis are suggested. Similarly, future research should focus on the long term outcomes of different treatment modalities through comparative trials.

Keywords: Cerebral palsy; Child; Crouch gait; Knee; Spastic diplegia.

Fig. 1

Characteristics of crouch gait. A & B—Flexion at hip and knee, dorsiflexion at ankle, rotational deformities in femur and tibia. C—Planovalgus foot deformity. D—Fixed flexion deformity at knee

Fig. 2

Etiopathology of crouch gait

Fig. 3

Popliteal angle test and hamstring shift test. The patient lies supine on a couch with both hip and knee extended. [A] – R1 position showing a value of 86°. [B] – R2 position showing improvement in popliteal angle with a value of 60°. [C] – Hamstring shift test showing further correction of the knee flexion deformity and popliteal angle of 38º

Fig. 4

Image 1 & 2 represent the knee kinematic and dynamic muscle tendon length–semimembranosus muscle of 14-year-old with spastic cerebral palsy. Image 3 & 4 represent knee kinematics and dynamic muscle tendon length (DMTL) of 17 year old with spastic CP

Fig. 5

Radiological evaluation of crouch gait. [A] AP radiograph of pelvis and both hips showing dysplastic changes and increased uncovering of femoral head (migration index = 60%) on right side. Coxa valga (neck shaft angle = 152.4°) is present on left side. [B] Frog leg lateral radiograph of same patient showing dysplastic changes on right side. [C] Lateral radiograph of knee showing patella alta (Insall Salvati Index = 1.57, Koshino Index = 1.35) [D] Plano valgus deformity in foot

Fig. 6

Case example of a patient with crouch gait treated surgically. [A & B] Preoperative clinical images [C & D] Post-operative clinical images [E & F] Post-operative radiographs showing correction of knee deformities and lever arm dysfunction