Introduction

Normal gait requires coordinated action of the hip abductors, adequate hip range of motion, a stable painless joint, equal or near-equal limb length and intact neuromuscular control.

Hip pathology commonly alters gait because of:

• Pain
• Abductor weakness
• Hip stiffness or deformity
• Limb-length discrepancy
• Instability
• Neurological dysfunction

A. Trendelenburg Gait

Trendelenburg gait is an abnormal gait caused by failure of the hip abductor mechanism of the stance limb to stabilize the pelvis during single-leg stance.

The principal abductors are:

• Gluteus medius
• Gluteus minimus
• Tensor fasciae latae as an accessory abductor

They are supplied predominantly by the superior gluteal nerve.

Normal Hip-Abductor Biomechanics

During single-leg stance, body weight produces an adduction moment about the hip and tends to make the pelvis drop on the unsupported side.

The abductors of the stance side contract to generate an opposing abduction moment and maintain the pelvis approximately level.

                 BODY WEIGHT
                     ↓
              unsupported side
                     │
                     ↓
            Adduction moment
                     ↘
     -------------------------------
       pelvis should remain level
     -------------------------------
               O  Hip joint
              ↙
       Abductor force
     (gluteus medius/minimus)

Abductor moment ≈ Body-weight moment

Trendelenburg Test

Method

1. Patient stands facing the examiner.