MSK lecture 1 & 2 Flashcards
When talking about physical tests, what are the 6 important things to always keep in mind?
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)
What are some reasons why we do physical tests?
- 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
What are the three basic types of muscle contractions?
The three basic types are dynamic (movement involved), isometric (no movement), and isokinetic (controlled speed)
How do we know if someone is getting stronger (in terms of muscle mass)?
they have more muscle
What is strength?
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.
What are some things that can affect how much strength someone has? (Think of things we can and cannot easily change during testing).
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.
How does the size of a muscle (cross-sectional area - CSA) relate to its strength?
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.
How does the length of a muscle affect its contractions?
Longer, thinner muscles are better for faster contractions, while shorter, thicker muscles are better for producing more force
What is pennation in a muscle, and how does it affect strength?
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
What is fatigue, and how can it affect strength testing?
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.
What is Post-activation Potentiation (PAP)?
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
How does the angle of a joint affect the strength you can produce?
The joint angle matters a lot! Muscles have different strength capacities at different positions in the range of motion
What is a motor unit?
A motor unit is one nerve cell (alpha motor neuron) and all the muscle fibers it connects to
What is a motor pool?
A motor pool is all the nerve cells that control a single muscle.
What is Maximum Voluntary Contraction (MVC)?
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.
What are the main types of strength measurements?
The main types are dynamic (like lifting weights through a range of motion), isometric (holding a position), and isokinetic (moving at a constant speed).
What is a 1 Rep Max (1RM) test?
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
What are some important things to consider when doing a 1RM test to keep it safe and accurate?
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.
Is a 1RM test a reliable way to measure strength?
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
Are there any groups of people who should be cautious or avoid 1RM testing?
Yes, 1RM testing is not recommended for certain groups
What is a Multiple Rep Max (mRM) test?
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.
How can you estimate someone’s 1RM if you know their mRM (how many reps they can do with a certain weight)?
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.
Are mRM tests as reliable as 1RM tests?
Yes, reliability and validity are similar between mRM and 1RM testing.
Are there differences in how many reps people can do at a certain percentage of their 1RM for different exercises?
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
What is isometric strength testing?
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
What are some important things to control during an isometric strength test?
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
What is a handgrip dynamometer, and what can it tell us?
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
What is isokinetic dynamometry?
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.
What are some advantages and disadvantages of isokinetic dynamometers?
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.
How does strength change as people get older?
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
What are some strength tests that are specifically used for older adults?
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
What is power?
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.
What is the formula for power?
Power = Force x Velocity. This means you need to be both strong and fast to have good power.
When do you produce the most force versus the most power during a muscle contraction?
You produce the most force during an isometric (no movement) contraction. Peak power happens at an optimal, high velocity
Do athletes usually have a lot of time to develop maximum force in their movements?
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
Why is power important for athletes?
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
Why is power important for overall health?
A certain level of power is needed for basic movements, everyday tasks, staying independent, and being physically active, especially as people age.
What are some ways to measure muscular power in a lab?
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
What are some more practical ways to assess power?
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
What is the Vertical Jump test?
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
What are some different ways to perform and measure a Vertical Jump?
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
What is the Countermovement Jump (CMJ)?
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
What is the Squat Jump (SJ)?
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
What is Explosive Strength Deficit (ESD)? How is it calculated and what does it tell us?
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
What is the Long Jump or Broad Jump, and what does it measure?
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
What is the Reactive Strength Index (RSI)? What do you need to measure it?
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.
What is the Seated Med Ball Throw, and what does it test?
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.
What kind of technology can be used to monitor movement speed in powerlifting exercises?
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.
What does “stability must precede force expression” mean?
This means that you need to have good stability and control of your body before you can effectively generate maximum force or power
What is muscular endurance?
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).
What are some general things to think about when testing muscular endurance?
You need to consider whether the test will start at a maximum effort or less than maximum (submaximal)
What are the two main types of muscular endurance tests?
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)
What are some common ways to determine the endpoint of a muscular endurance test?
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
What are some things that can cause muscle fatigue?
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
How can you test muscular endurance using weights?
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
In a test where someone does as many repetitions as they can (mRM), when does it become more about endurance than strength?
Generally, doing less than 10 repetitions tends to focus more on strength, while doing more than 20 repetitions often emphasizes muscular endurance.
What are some important things to consider when doing push-up tests for endurance?
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
Describe the standard push-up.
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.
Describe the hand-release push-up.
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.
What is a pull-up test for endurance?
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
What is a chin-up? How is it different from a pull-up?
A chin-up is similar to a pull-up, but typically uses an underhand grip (palms facing you)
What is the Biering-Sorensen Back Extension Test? What does it measure?
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).
What are some important things to consider when testing abdominal endurance (like curl-ups or sit-ups)?
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
Describe the partial curl-up test.
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)
Describe the “U of A” Sit-up Test and the “Hockey Entry Draft” Sit-up Test.
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
What is an example of an occupational muscular endurance test?
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
