MSK lecture 1 & 2

Question 1

When talking about physical tests, what are the 6 important things to always keep in mind?

Answer 1

Always think about Safety, making sure the test measures what it’s supposed to (Validity), that the results are consistent (Reliability), how exact the measurement is (Precision), if it’s easy to do (Practicality), and acting like a knowledgeable expert (Professionalism)

Question 2

What are some reasons why we do physical tests?

Answer 2

• To identify strengths and weaknesses and figure out good training amounts.
• To monitor and evaluate progress, plateaus, or decline.
• Testing helps with education, like creating exercise plans and giving feedback.
• Finally, it can be a health status indicator

Question 3

What are the three basic types of muscle contractions?

Answer 3

The three basic types are dynamic (movement involved), isometric (no movement), and isokinetic (controlled speed)

Question 4

How do we know if someone is getting stronger (in terms of muscle mass)?

Answer 4

they have more muscle

Question 5

What is strength?

Answer 5

Strength is ideally the maximum weight you can lift one time but not twice. It’s also thought of as the maximum force your muscles can produce.

Question 6

What are some things that can affect how much strength someone has? (Think of things we can and cannot easily change during testing).

Answer 6

Things that affect strength include muscle structure (architecture) like cross-sectional area (CSA), fiber type, and pennation angle, their history (like fatigue and post-activation potentiation), the position of their joints, and how their nervous system signals the muscles (neural drive) like recruitment and rate coding.

Question 7

How does the size of a muscle (cross-sectional area - CSA) relate to its strength?

Answer 7

A larger cross-sectional area generally means the muscle has more fibers that can directly contribute to force production, so it’s a good indicator of strength.

Question 8

How does the length of a muscle affect its contractions?

Answer 8

Longer, thinner muscles are better for faster contractions, while shorter, thicker muscles are better for producing more force

Question 9

What is pennation in a muscle, and how does it affect strength?

Answer 9

Pennation is the angle of the muscle fibers relative to the muscle’s tendon. More pennation means more force can be produced for a given muscle size, but it might sacrifice how fast the muscle can shorten

Question 10

What is fatigue, and how can it affect strength testing?

Answer 10

Fatigue is when your muscles get tired. It can greatly reduce the number of repetitions you can do, especially if there isn’t enough rest between sets.

Question 11

What is Post-activation Potentiation (PAP)?

Answer 11

Post-activation Potentiation (PAP) is a short-term increase in maximal force after doing a near-maximal muscle contraction. However, it’s tricky to measure directly, and factors like warm-up can also play a role

Question 12

How does the angle of a joint affect the strength you can produce?

Answer 12

The joint angle matters a lot! Muscles have different strength capacities at different positions in the range of motion

Question 13

What is a motor unit?

Answer 13

A motor unit is one nerve cell (alpha motor neuron) and all the muscle fibers it connects to

Question 14

What is a motor pool?

Answer 14

A motor pool is all the nerve cells that control a single muscle.

Question 15

What is Maximum Voluntary Contraction (MVC)?

Answer 15

Maximum Voluntary Contraction (MVC) is when you try your hardest to use as many muscle fibers as possible to create the most force for a movement.

Question 16

What are the main types of strength measurements?

Answer 16

The main types are dynamic (like lifting weights through a range of motion), isometric (holding a position), and isokinetic (moving at a constant speed).

Question 17

What is a 1 Rep Max (1RM) test?

Answer 17

A 1 Rep Max (1RM) test finds the heaviest weight you can lift correctly just one time. It’s often considered the best way to measure strength

Question 18

What are some important things to consider when doing a 1RM test to keep it safe and accurate?

Answer 18

Make sure the weight is accurate, do a good warm-up that’s specific to the exercise, avoid bouncing the weight, control the number of warm-up sets and reps without causing too much tiredness, allow enough rest between sets (about 3 minutes), and keep things like range of motion, joint angle, posture, grip, and timing consistent.

Question 19

Is a 1RM test a reliable way to measure strength?

Answer 19

Yes, 1RM tests are generally very reliable when done correctly. However, it might be harder to get a true 1RM in people who haven’t trained much

Question 20

Are there any groups of people who should be cautious or avoid 1RM testing?

Answer 20

Yes, 1RM testing is not recommended for certain groups

Question 21

What is a Multiple Rep Max (mRM) test?

Answer 21

A Multiple Rep Max (mRM) test is when you find the heaviest weight you can lift for a specific number of repetitions (like 6RM means the most weight you can lift 6 times). It’s an alternative to the 1RM test.

Question 22

How can you estimate someone’s 1RM if you know their mRM (how many reps they can do with a certain weight)?

Answer 22

There’s a general relationship between the percentage of your 1RM and the number of reps you can do. For example, if you can lift 125 lbs for 6 reps, you can use a formula (like Weight lifted / (% 1-RM / 100) = Estimated 1RM) or a chart to estimate your 1RM.

Question 23

Are mRM tests as reliable as 1RM tests?

Answer 23

Yes, reliability and validity are similar between mRM and 1RM testing.

Question 24

Are there differences in how many reps people can do at a certain percentage of their 1RM for different exercises?

Answer 24

Yes, for example, people tend to be able to do more reps with the leg press compared to the bench press at the same percentage of their 1RM. Also, leg press results can be more variable

Question 25

What is isometric strength testing?

Answer 25

Isometric strength testing measures the maximum force a muscle can produce without any movement. Tools like cable tensiometers, isokinetic dynamometers set to zero speed, and handgrip dynamometers are used. Some consider it the best way to measure strength

Question 26

What are some important things to control during an isometric strength test?

Answer 26

It's very important to control body position to isolate the muscles being tested, and the exact angle of the joint. You should also increase tension gradually and hold the maximum contraction for a few seconds

Question 27

What is a handgrip dynamometer, and what can it tell us?

Answer 27

A handgrip dynamometer measures the strength of your grip. It has a moderate link to overall upper body strength and can be used to screen for risk of physical disability related to low muscle strength, especially in older adults. Low scores can indicate higher health risks

Question 28

What is isokinetic dynamometry?

Answer 28

Isokinetic dynamometry uses a machine that controls the speed of movement while measuring the force you produce through a range of motion. It's useful for seeing how strength changes across the movement and for isolating muscle weaknesses.

Question 29

What are some advantages and disadvantages of isokinetic dynamometers?

Answer 29

Advantages include being able to isolate single joints and control the speed, allowing for isometric testing by setting the speed to zero. Disadvantages include being expensive, needing careful calibration, and the fact that people need to learn how to use them for accurate results. Testing multiple joints at once is difficult.

Question 30

How does strength change as people get older?

Answer 30

Strength typically starts to decline around age 45-50, at a rate of about 12-15% per decade. By their 60s or 70s, people can lose a large amount of their strength (25-40%), mostly due to muscle shrinking (atrophy). Women might experience a slightly higher percentage of strength loss than men

Question 31

What are some strength tests that are specifically used for older adults?

Answer 31

Two examples are the 30-second Arm-Curl Test (counts how many arm curls can be done with a light weight in 30 seconds) and the 30-second Chair Stand Test (counts how many times someone can stand up and sit down from a chair in 30 seconds). These tests relate to their ability to do everyday tasks

Question 32

What is power?

Answer 32

Power is how quickly you can do work. It's a rate, not an amount. In terms of muscles, it's the ability to generate force as quickly as possible.

Question 33

What is the formula for power?

Answer 33

Power = Force x Velocity. This means you need to be both strong and fast to have good power.

Question 34

When do you produce the most force versus the most power during a muscle contraction?

Answer 34

You produce the most force during an isometric (no movement) contraction. Peak power happens at an optimal, high velocity

Question 35

Do athletes usually have a lot of time to develop maximum force in their movements?

Answer 35

No, most athletic movements happen very quickly (within 300 milliseconds), so athletes don't have the luxury of time to build up to their maximum force. The goal is to increase force while also doing it faster

Question 36

Why is power important for athletes?

Answer 36

Maximum power is a key factor for success in sports that require high speed of the body or objects, like jumping high, cycling sprints, and running fast

Question 37

Why is power important for overall health?

Answer 37

A certain level of power is needed for basic movements, everyday tasks, staying independent, and being physically active, especially as people age.

Question 38

What are some ways to measure muscular power in a lab?

Answer 38

Some "gold standard" lab tools include force plates, load/linear placement transducers, electronic goniometers, and kinematic analysis. However, these can be expensive and not very practical

Question 39

What are some more practical ways to assess power?

Answer 39

More accessible methods include tests like the stand up and go test (for older adults), using a Vertec (jump height measurement tool), a jump mat, or even some phone apps that measure time

Question 40

What is the Vertical Jump test?

Answer 40

The Vertical Jump (VJ) test measures how high someone can jump. It's thought to be a power test because it's explosive and involves moving your body weight against gravity

Question 41

What are some different ways to perform and measure a Vertical Jump?

Answer 41

You can use a wall and chalk, a Vertec device, a jump mat, or an Optojump system. There are also different versions like the Countermovement Jump (CMJ) (allowing a dip before jumping), Squat Jump (SJ) (starting in a squat), one-leg vs. two-leg jumps, and using arms or not

Question 42

What is the Countermovement Jump (CMJ)?

Answer 42

The Countermovement Jump (CMJ) is a vertical jump where you start standing, quickly go down into a squat (eccentric phase), and then immediately jump up as high as you can (concentric phase), often using your arms

Question 43

What is the Squat Jump (SJ)?

Answer 43

The Squat Jump (SJ) is a vertical jump where you start in a squat position, hold it briefly (2-3 seconds), and then jump straight up without the initial downward movement of a CMJ

Question 44

What is Explosive Strength Deficit (ESD)? How is it calculated and what does it tell us?

Answer 44

Explosive Strength Deficit (ESD) compares how high you jump in a CMJ versus an SJ. It's calculated as 100 x (CMJ - SJ) / CMJ. A low score (0-10%) might mean you need to work on your ability to use the stretch-shortening cycle (the down-up movement), while a high score (over 11%) could suggest you have good explosive ability but might benefit from more traditional strength training

Question 45

What is the Long Jump or Broad Jump, and what does it measure?

Answer 45

The Long Jump (or Broad Jump) measures how far you can jump horizontally from a standing start. It's harder to convert to power units because it has both vertical and horizontal components. It's used in various populations and can be a good indicator of overall athletic ability

Question 46

What is the Reactive Strength Index (RSI)? What do you need to measure it?

Answer 46

The Reactive Strength Index (RSI) assesses "explosiveness" and how well you use the stretch-shortening cycle during power tasks. You need to measure jump height and contact time with the ground (often using a jump mat) after dropping from a certain height (like a 30 cm box). RSI = Jump height / contact time.

Question 47

What is the Seated Med Ball Throw, and what does it test?

Answer 47

The Seated Med Ball Throw involves throwing a medicine ball as far as you can while seated. It's commonly used to assess upper body power, especially in sports like hockey.

Question 48

What kind of technology can be used to monitor movement speed in powerlifting exercises?

Answer 48

Devices like linear position transducers (e.g., GymAware, FitroDyne/TENDO) and inertial sensors (e.g., PUSH, Beast Sensor) can track the speed of the barbell during exercises like bench press, squat, and deadlift. Linear position transducers are generally more accurate.

Question 49

What does "stability must precede force expression" mean?

Answer 49

This means that you need to have good stability and control of your body before you can effectively generate maximum force or power

Question 50

What is muscular endurance?

Answer 50

Muscular endurance (ME) is the ability to keep a muscle contracted or to repeat muscle contractions for a long time until you get tired (fatigue).

Question 51

What are some general things to think about when testing muscular endurance?

Answer 51

You need to consider whether the test will start at a maximum effort or less than maximum (submaximal)

Question 52

What are the two main types of muscular endurance tests?

Answer 52

The two types are submaximal ME tests, which start at a lower intensity and go until a limit is reached (e.g., holding a back extension), and maximal ME tests, which start at a maximal effort and continue until fatigue (e.g., holding a grip at a high percentage of your maximum strength until it drops)

Question 53

What are some common ways to determine the endpoint of a muscular endurance test?

Answer 53

Endpoints can be based on how long someone can hold a contraction, reaching a set number of repetitions, a drop in performance (like strength decreasing by a certain percentage), or simply reaching exhaustion. Often, the speed or timing of the movements is controlled

Question 54

What are some things that can cause muscle fatigue?

Answer 54

Muscle fatigue can be caused by things happening within the muscle like reduced blood flow, running out of energy (glycogen), build-up of metabolic byproducts, and the type of muscle fibers you have. It can also be due to the nervous system not signaling the muscles as well, your tolerance to feeling tired, and your motivation. The specific rules of the test also matter

Question 55

How can you test muscular endurance using weights?

Answer 55

You can use free weights or machines and have someone perform repetitions until they can't anymore, either at a certain percentage of their 1RM or with a fixed weight. The pace can be controlled with a metronome

Question 56

In a test where someone does as many repetitions as they can (mRM), when does it become more about endurance than strength?

Answer 56

Generally, doing less than 10 repetitions tends to focus more on strength, while doing more than 20 repetitions often emphasizes muscular endurance.

Question 57

What are some important things to consider when doing push-up tests for endurance?

Answer 57

Hand placement, foot placement (on toes or knees), maintaining a rigid body form, going down to the correct depth (upper arms parallel to the floor), and how resting is allowed are all important factors. The test can end when they can't do any more correct repetitions or after a set time

Question 58

Describe the standard push-up.

Answer 58

Start with hands slightly wider than shoulder-width, lower your body until your upper arms are parallel to the floor (90-degree elbow bend), then push back up to a full arm extension. Keep a straight line from head to heels.

Question 59

Describe the hand-release push-up.

Answer 59

Start lying on your stomach with hands under your shoulders. Push your whole body up. Lower back down until chest, hips, and thighs touch. Then lift your hands off the ground into a "T" position, return them under your shoulders, and push back up.

Question 60

What is a pull-up test for endurance?

Answer 60

A pull-up test measures the maximum number of consecutive pull-ups someone can do with an overhand grip, starting with arms straight and pulling up until their chin is above the bar. There are variations, and the test ends when they can no longer complete a full repetition

Question 61

What is a chin-up? How is it different from a pull-up?

Answer 61

A chin-up is similar to a pull-up, but typically uses an underhand grip (palms facing you)

Question 62

What is the Biering-Sorensen Back Extension Test? What does it measure?

Answer 62

The Biering-Sorensen Back Extension Test assesses the muscular endurance of the lower back. You hold your upper body horizontal while your lower body is supported. The test usually goes until fatigue or a set time limit (like 180 seconds).

Question 63

What are some important things to consider when testing abdominal endurance (like curl-ups or sit-ups)?

Answer 63

Body position, the range of motion of the movement, whether you control the speed of repetitions (often with a 1:1 tempo around 25 reps per minute), and having clear stopping rules are all important

Question 64

Describe the partial curl-up test.

Answer 64

In a partial curl-up, you lie on your back with knees bent and feet flat. You curl your upper body up until your shoulder blades leave the ground, reaching a specific distance mark (different for different age groups)

Question 65

Describe the "U of A" Sit-up Test and the "Hockey Entry Draft" Sit-up Test.

Answer 65

The "U of A" Sit-up Test is like a partial curl-up, but your fingers must stay behind your ears until your elbows touch your thighs. The "Hockey Entry Draft" Sit-up Test is similar, but your arms are crossed over your chest with each hand on the opposite shoulder

Question 66

What is an example of an occupational muscular endurance test?

Answer 66

The Sandbag lift requires lifting a 20 kg sandbag from the floor to above 1.0 m height 30 times in under 3 minutes and 30 seconds, alternating sides. This tests the endurance needed for certain job tasks