Mock Exam Questions Flashcards
What is Biomechanics?
Biomechanics is the science that examines forces acting upon and within biological structures and effects produced by such forces
What are the main differences, in the context of biomechanics, that differentiate running from walking
In running….
The varus angle of the lower limb is increased
The magnitude of ground reaction force is increased
The velocity of rearfoot pronation is increased
There is no period of double limb support, the single support phase is separated by a flight phase
Gait is comprised of 40% stance phase and 60% swing phase, with increased speed stance phase continues to decrease; sprinting = 20% stance phase and 80% swing phase
Stride length and frequency is increased. Increased stride frequency increases energy cost
Muscle activity is increased in all phases of gait, for example gastrocnemius and soleus are active only during stance phase in normal walking gait, but are active in both stance and swing in running gait
Lower extremity muscles involved in running demonstrate their highest level of EMG activity during terminal swing, when they are preparing for ground contact, as opposed to walking where the highest EMG activity occurs during midstance and propulsion
Maximal ground reaction force is 2-3 x body weight
The activity of which lower limb muscle compartment is increased during stance phase in barefoot running?
The posterior compartment
What ligament is most commonly injured in a lateral ankle sprain?
The Anterior Talo-Fibular Ligament (ATFL)
What clinical assessment can be carried out to assess the stability of ATFL?
The anterior drawer test
What causes exertional compartment syndrome?
When you exercise, your muscles expand in volume, exertional compartment syndrome occurs when the fascial sheath that encases the affected muscle fails to stretch sufficiently.
Name four biomechanical risk factors that put women at greater risk of anterior cruciate ligament (ACL) injuries?
Increased femoral anteversion - a condition where the femoral neck leans forward excessively in comparison to the femoral shaft, causing the femur to be internally rotated
Increased ‘Q’ angle - the angle created when a line is drawn from the ASIS to the centre of the patella, and from the centre of the patella to the tibial tubericle. In women, the angle should be between 10° - 22°. Increased Q angle is associated with coxa vara and Genu valgum malaligments. Women typically have a higher Q angle value than men as women typically have wider a wider pelvis, meaning the femoral heads will be further apart at their articulations with the pelvis.
Excessive tibial torsion -
Excessive STJ pronation related to ligamentous laxity
What two hormones are associated with ligamentous laxity in female athletes?
Oestrogen & Progesterone
Name some intrinsic factors that can contribute to the development of an overuse injury?
Age
Weight
Sex
Anatomical Variations
Biomechanics
Fitness Level
Psychology
A 30yr old female attends your clinic complaining of swelling and tenderness at the inferior pole of her patella, to try and keep fit she had taken up running a few months ago, recently her training schedule has been increased as she has been training for a half marathon. You assess the patient and diagnose patellar tendinopathy.
Name some differential diagnoses for these symptoms described above.
Chondromalacia Patellae (AKA ‘Runner’s Knee’) - Softening and degeneration of the articular cartilage of the patella, causing pain at the anterior knee
Hoffa’s Pad Syndrome - Inflammation of the infrapatellar fat pad (Hoffa’s fat pad - located at the anterior aspect of the inferior knee joint, behind the patella and patella tendon) due to repetitive trauma/ irritation of the fat pad (sometimes associated with knee hypermobility/hyperextension)
Iliotibial Band Friction Syndrome - Pain in the region of the lateral femoral condyle, linked to irritation of the iliotibial band being repetitively shifted backwards and forwards over the lateral femoral condyle, during activities involving repetitive knee flexion, causing friction.
Patella Femoral Syndrome - Diffuse pain at the anterior knee, with tenderness around the borders of the patella. Caused by abnormal articulation of the patella and the femur, typically by abnormal femoral internal rotation and STJ pronation. As the quads pull the patella into contact with the femur, if it is internally rotated the patella is pulled laterally onto the femur, meaning that less of the patella’s surface area is in contact with femur. This increases the force going through the patella as there is less surface area to dissipate the pressure.
Knee Osteoarthritis
Osteochondral lesion of the knee
