CSCS Chapter 4

During the initial weeks of resistance training, the increase in strength is primarily attributed to neural control. This is because the brain learns to activate and coordinate the muscles more efficiently, leading to improved muscle recruitment and contraction. Neural adaptations, such as increased motor unit activation and synchronization, play a significant role in enhancing strength and performance. This is often referred to as "brain learning" as the central nervous system adapts and becomes more efficient in controlling the muscles during resistance exercises.

The correct answer is Axial. The axial skeleton consists of the skull, vertebral column, ribs, and sternum. This part of the skeletal system provides support and protection for the vital organs, such as the brain and spinal cord. It also plays a role in maintaining posture and facilitating movement. The appendicular skeleton, on the other hand, includes the bones of the limbs and the girdles that attach them to the axial skeleton.

The statement is false because the patella and surrounding tissue are actually highly susceptible to the forces encountered in resistance training. Resistance training involves putting stress on the muscles and joints, and the patella and surrounding tissue can be affected by these forces. In fact, patellar tendonitis, which is inflammation of the patellar tendon, is a common injury among individuals who engage in resistance training. Therefore, it is incorrect to say that the patella and surrounding tissue are the least susceptible to these forces.

The force a muscle exerts is related to the cross-sectional area of the muscle rather than the volume because the cross-sectional area is directly proportional to the number of muscle fibers that can contract simultaneously. When a muscle contracts, the force it generates is a result of the collective force produced by all the contracting muscle fibers. Therefore, a larger cross-sectional area means more muscle fibers can contract, resulting in a greater force production. The volume of the muscle, on the other hand, does not directly impact the force generated.

When an athlete tries to move an object that is pressed against another object, they will encounter a resistive force known as friction. Friction occurs when two surfaces are in contact with each other and there is relative motion or an attempt to move. In this scenario, the surfaces of the objects and the pressure between them will create friction, making it difficult for the athlete to move the object smoothly.

Fluid resistance machines do not provide optimal training for sport movements that involve eccentric muscle action such as running, jumping, or throwing because they lack eccentric muscle action. Eccentric muscle action is important for deceleration, force absorption, and generating power, which are all crucial for sports movements. Therefore, the lack of eccentric muscle action in fluid resistance machines makes them less effective for training in sports that require these movements.

The weight stack machine does not provide simulation of real-life activities. This means that the movements or exercises performed on this machine may not mimic the natural movements required for activities in everyday life. While weight stack machines offer other advantages such as safety, design flexibility, and ease of use, they may not effectively replicate real-life movements.

Negative work and power occur during eccentric muscle activity. Eccentric muscle contractions happen when the muscle lengthens while generating force. This occurs when the external load or resistance is greater than the force generated by the muscle. During eccentric contractions, the muscle acts as a brake to control the movement and decelerate the body or an object. This type of muscle activity is commonly seen when lowering weights or controlling movements during activities such as running downhill or descending stairs.

A first-class lever is a type of lever where the muscle force is applied on the opposite side of the fulcrum from the resistive force. This means that the force exerted by the muscles is used to overcome the resistance, such as extending the forearm at the elbow joint. The term "first" or "1st" is used to refer to this specific type of lever.

When a weight is horizontally closer to a joint, it exerts less resistive torque compared to a weight that is horizontally farther away from the joint. This is because the distance between the weight and the joint, known as the lever arm, affects the torque. The shorter the lever arm, the less torque is produced. Therefore, when the weight is closer to the joint horizontally, the lever arm is shorter and the resistive torque is reduced.

Hip flexion and extension occur in the sagittal plane. The sagittal plane divides the body into left and right halves, and movements in this plane involve forward and backward motions. When the hip joint flexes, it moves the thigh bone forward, and when it extends, it moves the thigh bone backward. Therefore, hip flexion and extension primarily occur in the sagittal plane.

When a muscle is fully contracted, it is actually at its shortest length and cannot generate the greatest force. The greatest force is generated when the muscle is at an intermediate length, allowing for optimal overlap of actin and myosin filaments.

For slow movements like power-lifting, having tendon insertion farther from the joint than normal can be advantageous. This is because a longer lever arm can provide a mechanical advantage, allowing the muscles to generate more force. With the tendon inserted farther from the joint, the moment arm of the muscle is increased, resulting in greater torque production and improved performance in slow, strength-based movements.

The knee joint is actually an example of a synovial joint, not a cartilaginous joint. Cartilaginous joints are characterized by the presence of cartilage between the bones, which allows for limited movement. In the knee joint, however, there is a synovial cavity filled with synovial fluid, which allows for a wide range of movement.

The given correct answer states that the muscle type "Radiate" is not matched with the correct muscle example "biceps brachii." However, the biceps brachii is actually an example of a radiate muscle. Radiate muscles have fibers that radiate or converge from a central tendon, which is the case with the biceps brachii. Therefore, the given answer is incorrect.

The best back lifting posture to avoid injury is a flat-back. This means keeping the back straight and aligned with the hips and shoulders. Maintaining a flat-back posture during lifting helps distribute the weight evenly and reduces the strain on the spine. It also promotes proper muscle engagement and stability, minimizing the risk of injury to the back.

The Valsalva maneuver is a technique used to create intra-abdominal pressure by closing the glottis and contracting the muscles of the abdomen. While athletes may use the Valsalva maneuver in certain situations, it is not the only way to create intra-abdominal pressure. Other techniques such as bracing the core and engaging the diaphragm can also be used to create intra-abdominal pressure during exercises like lifting heavy weights. Therefore, the statement that athletes must use the Valsalva maneuver to create intra-abdominal pressure is false.

Force (Weight) = 9.8 m/s2 x 100 kg = 980 N

Work = Force x Distance
Work = 980 N x 2 m = 1960 J

The triceps muscle is responsible for extending the arm when throwing a ball, making it the agonist muscle. The biceps muscle, on the other hand, performs the opposite action of flexing the arm, making it the antagonist muscle. The scapular stabilizers work in synergy with the triceps and biceps muscles to ensure proper shoulder movement and stability during the throwing motion.