a. Name two forearm muscles that are powerful extensors and abductors of the hand. b. Name the sole forearm muscle that can flex the distal interphalangeal joints.

Video transcript

Hi, everyone. Let's take a look at this practice problem together. Which of the following is the main extensor muscle of the hip in humans. The answer options are a gluteus, maximus, B, hamstring muscles, C quadriceps, pho Morris, and D, the, so a major. Ok. We need to identify the main muscle for hip extension. Now, this movement is like going from a curled up ball position to putting your legs straight out. That would be hip extension. Now, option D the, so a major, this is a very deep muscle. It's located from the lumbar region of the spine down to its insertion on the femur. So when it contracts, it will cause hip flexion. So option D is incorrect. Option C, the quadriceps for Morris, this is a muscle on the anterior thigh and it crosses the knee joint. And so as a prime mover of knee extension. So option C, we can also eliminate. Now, the hamstring muscles are on the posterior aspect of the thigh and the hamstring muscles actually cross two joints, both the hip joint and the knee joint. Thus, they produced both knee flexion and hip extension. So this is a possible answer choice. But let's go ahead and talk about that last answer option. The last answer option, gluteus maximus we should know is a very strong muscle and it's the primary primary mover of hip extension. So it's the gluteus maximus, that's the main hip extensor. Whereas the hamstrings just assist with that hip extension, that means the correct answer is option. A gluteus maximus. All right, everyone. I hope you found this helpful and I'll see you soon for the next practice problem.