Osteoarthritis (OA) is a chronic disease affecting the joint and its tissues, primarily
leading to progressive damage to articular cartilage and, subsequently, to the
subchondral bone and surrounding synovial structures. This chronic degenerative disease
affects approximately one-third of adults, and its prevalence increasing with advancing
age. The knee is one of the most common joints affected by the OA. Systematic reviews
indicate a global prevalence of knee osteoarthritis (KOA) is 22.9% among individuals aged
40 and older, affecting an estimated 654.1 million people worldwide, with variations
across countries and increasing with age.
Knee osteoarthritis (KOA) is a multi etiological, chronic disabling disease that affects
the entire knee joint, which is the most common site of involvement in OA. KOA patients
mostly suffer from progressive stiffness and knee pain. Gradually, they have some
difficulties in performing daily activities, such as walking, squatting, and climbing and
doing housework, as the disease progresses. Ultimately, pain and disability associated
with the disease lead to a loss of functional independence and a profound reduction in
quality-of- life. Impairments that are caused by KOA include knee pain, limited ROM of
the knee, muscle weakness and knee instability.
The hip abductor muscles influence knee joint loading through their control of the pelvis
in the frontal plane. Researchers have proposed that during the single-limb stance phase
of gait, weakness of the stance-limb hip abductor muscles may lead to drop of the pelvis
toward the contralateral limb, shifting the body's center of mass away from the stance
limb toward the swing side. These adjustments, theoretically, could lead to higher knee
adduction moments and greater medial knee joint loading.
Knee adduction moment is the moment that acts on the joint in the frontal plane. The knee
adduction moment is generated by the combination of the ground reaction force, which
passes medial to the centre of the knee joint during gait, and the perpendicular distance
of this force from the centre of the joint. . This moment tends to adduct the
tibiofemoral joint, causing an increase in medial compartment pressure, and people with
knee OA have demonstrated larger than normal peak knee adduction moments in their gait
patterns.
OA of the knee is characterized by changes in gait kinematics. High dynamic loads of the
medial knee, as assessed by the external peak knee adduction moment, have been associated
with tibiofemoral OA severity progression, and knee pain. The aging process impairs
postural control more in a medial-lateral (ML) direction than in an anterior-posterior
(AP) direction, which is linked with increased falling risk. Postural control stability
in the ML direction, in orthostatic stance and during compensatory step, is dependent on
hip abductor-adductor muscle torque .The hip abductor muscles are also needed to
stabilize the lumbar-pelvic joint during gait and during balance recovery after external
disturbance (postural responses of hip and step) This study aims to find the effect of
hip abductor strengthening exercises on improving range of motion, functional activities,
balance and minimizing pain in individuals affected by the knee OA.