If this is true it could force the transfer fee back up after the Portuguese club apparently dropped it earlier this week. (justarsenal.com)
When the thighs push your body backwards against the bench, this results in force transfer upwards to the bar. (fitnessandpower.com)
The muscular forces transferred from the thigh muscles to the lower leg utilise the kneecap as a pulley system, and if these forces are not completely vertical, there is a tendency for a pull on the patella to the medial or inner side of the knee, which causes the instability. (petsmagazine.com.sg)