Force Plate Testing

Objective measurement of strength, balance, power and movement

Force plate testing uses specialised equipment to measure the forces you produce against the ground during movements such as standing, jumping, landing or pushing through one or both legs.

It can provide detailed information about strength, power, balance, symmetry and how force is produced or absorbed during movement.

Force plate testing may be useful for athletes, people progressing through rehabilitation and those returning to higher-level sport after injury.

The aim is not simply to generate numbers. The results should help identify meaningful physical differences, monitor progress and guide training or rehabilitation decisions.

What is force plate testing?

A force plate is a platform containing sensors that measure how much force is applied to the ground.

When you stand, jump, land or perform another movement on the plate, the system can record information such as:

• Force production
• Rate of force development
• Jump height
• Power
• Weight distribution
• Balance
• Landing forces
• Differences between sides
• Movement timing

Depending on the equipment and test used, measurements can be recorded from one or both legs.

The results are then interpreted alongside your injury history, strength, movement and sporting goals.

Who may benefit from force plate testing?

Force plate testing may be useful if you:

• Are returning to sport after injury
• Want objective strength or power measurements
• Are recovering after knee or ankle surgery
• Have a history of lower-limb injuries
• Want to monitor athletic development
• Are completing a strength and conditioning programme
• Want baseline measurements before a season
• Are preparing for higher-level sport
• Want to compare physical performance over time
• Are working on jumping or landing
• Need more detailed information than visual movement assessment alone can provide

You do not need to be injured to complete testing.

What happens during the assessment?

The session begins with a discussion about your current training or rehabilitation.

You may be asked about:

• Your sport
• Competition level
• Previous injuries
• Previous surgery
• Current symptoms
• Current gym training
• Running or jumping activity
• Rehabilitation completed
• Your goals

The clinician can then select tests that are relevant to your needs.

You may be asked to complete:

• Quiet standing
• Squats
• Sit-to-stands
• Isometric strength tests
• Countermovement jumps
• Squat jumps
• Single-leg jumps
• Drop landings
• Repeated jumps

Not every person needs every test.

What can force plates measure?

Force plates can provide several types of information depending on the test.

Force

Force describes how hard you push against the ground.

This can provide information about:

• Strength
• Weight distribution
• Differences between limbs

Power

Power considers how quickly force is produced.

It can be particularly relevant for:

• Jumping
• Sprinting
• Explosive sport
• Rapid movements

Rate of force development

Rate of force development describes how quickly force rises.

This can be useful when assessing movements where force must be produced rapidly, such as:

• Sprint starts
• Jumping
• Direction changes

Balance

During standing tasks, force plates can measure small movements in how body weight shifts across the platform.

This may provide objective information about:

• Postural control
• Weight distribution
• Stability

Landing force

Force plates can measure how the body absorbs force when landing.

This may be useful during:

• Return-to-sport testing
• Jump rehabilitation
• Lower-limb injury assessment

Countermovement jump testing

The countermovement jump is one of the most commonly used force plate tests.

You begin standing before quickly bending and jumping upwards.

The force plate may provide information about:

• Jump height
• Peak force
• Power
• Movement strategy
• Differences between legs

The test can be useful for athletes involved in running, jumping or explosive sport.

It can also be repeated over time to monitor progress.

Squat jump testing

A squat jump usually begins from a held squat position before jumping upwards.

This can provide different information from a countermovement jump because there is less contribution from the rapid downward movement beforehand.

Testing may help assess:

• Explosive strength
• Power
• Ability to produce force from a static position

The test chosen depends on the physical qualities being assessed.

Single-leg jump testing

Single-leg testing can provide more specific information about each limb.

This may be useful after:

• Knee injury
• Ankle injury
• Lower-limb surgery
• Long periods away from sport

The assessment may look at:

• Force production
• Jump height
• Balance
• Landing
• Differences between sides

Single-leg results can help identify whether one limb is still performing differently.

Repeated jump testing

One successful jump does not tell us how well an athlete can repeat effort.

Repeated jumping may provide additional information about:

• Power
• Fatigue
• Reactive ability
• Ability to maintain performance

This may be particularly relevant in sports such as:

• Basketball
• Volleyball
• Netball
• Football

where jumping occurs repeatedly rather than only once.

Landing assessment

Landing tests may involve stepping or dropping from a platform and landing on one or both force plates.

The system can measure how quickly and how strongly force is absorbed.

The assessment may consider:

• Peak landing force
• Differences between legs
• Timing
• Stability after landing

These measurements can complement visual assessment of:

• Knee control
• Hip control
• Trunk movement

A high-quality return-to-sport assessment usually considers both the force data and how the movement is performed.

Strength testing

Some force plate systems can also be used during isometric strength tests.

An isometric contraction involves producing force without significant joint movement.

Depending on the setup, this may provide information about:

• Maximum force
• Speed of force production
• Differences between sides

This can provide useful baseline measurements during rehabilitation or athletic development.

Weight distribution

Force plates can measure how much body weight is placed through each side.

This may be particularly useful after:

• Lower-limb surgery
• Fracture
• Knee injury
• Hip injury

Some people continue to favour one side even after pain improves.

Objective measurement can help identify whether this difference remains.

Balance testing

Force plates may also be used during standing balance assessments.

Testing can look at how body pressure shifts while standing:

• With feet together
• On one leg
• With different visual conditions
• During selected balance tasks

The results can be useful alongside normal balance and neurological assessment.

Balance performance should still be interpreted according to the person’s age, condition and functional goals.

Force plate testing after ACL rehabilitation

Force plate testing may form part of later rehabilitation after ACL injury or reconstruction.

Testing can help assess areas such as:

• Jump performance
• Force production
• Landing
• Differences between limbs
• Weight distribution

An athlete may achieve similar jump heights with each leg while still using different force strategies.

More detailed force data can sometimes identify differences that are not obvious from distance or visual observation alone.

Force plate testing should still be combined with:

• Strength testing
• Hop testing
• Running
• Change-of-direction assessment
• Sport-specific rehabilitation

No single force plate result should determine return to sport by itself.

Force plate testing after knee injury

Knee injuries may affect how force is produced and absorbed.

An athlete may unconsciously:

• Push more through the uninjured leg
• Land more heavily on one side
• Generate less force through the injured leg

Force plate testing can help quantify these differences.

The findings can then guide further work on:

• Quadriceps strength
• Jumping
• Landing
• Single-leg power

Force plate testing after ankle injury

An ankle injury may affect:

• Push-off
• Landing
• Balance
• Force production

Force plate testing may help identify whether these qualities have returned before progressing to higher-level sport.

Rehabilitation may then include:

• Calf strengthening
• Hopping
• Landing
• Running
• Direction changes

Force plate testing after surgery

Following lower-limb surgery, force plate testing can sometimes provide useful objective measurements during later rehabilitation.

The timing depends on:

• Type of surgery
• Healing
• Current strength
• Medical restrictions

Testing should only be introduced once the person is ready for the physical demands of the selected task.

Return-to-sport testing

Force plate testing can form one part of a wider return-to-sport assessment.

Depending on the injury and sport, testing may also include:

• Strength
• Hop tests
• Running
• Sprinting
• Agility
• Changes of direction
• Sport-specific drills

Force plate data can provide additional information about:

• Power
• Symmetry
• Landing
• Force production

It should support the wider decision rather than replace it.

Force plate testing for athletes

Athletes without injury may use force plates to monitor physical qualities such as:

• Jump power
• Explosive strength
• Balance
• Fatigue

The results can help guide:

• Strength training
• Power training
• Pre-season preparation
• Performance monitoring

Testing should be selected according to the demands of the sport.

Football

Football requires:

• Sprinting
• Jumping
• Cutting
• Repeated high-intensity movement

Force plate testing may help assess:

• Lower-body power
• Jumping
• Single-leg differences
• Landing

Results may be useful when planning strength and conditioning.

Rugby

Rugby requires high levels of:

• Strength
• Power
• Running
• Contact tolerance

Force plate testing may help monitor:

• Jump performance
• Lower-body force
• Explosive power

Other physical testing is still needed to assess the wider demands of rugby.

Basketball and netball

Repeated jumping and landing make force plate testing particularly relevant to court sports.

Testing may look at:

• Jump height
• Repeated jump performance
• Landing forces
• Single-leg differences

This information can help guide power and landing training.

Running

Distance runners do not necessarily require maximum jump performance, but force plate testing may still provide information about:

• Lower-limb power
• Calf and leg capacity
• Side-to-side differences

For running injuries, these results should be considered alongside running assessment and training volume.

Sprinting

Sprinters require rapid force production.

Force plate testing may help assess:

• Explosive strength
• Rate of force development
• Jump power

However, actual sprint testing remains important because gym and jump performance do not fully replicate running at high speed.

Teenage athletes

Force plate testing can also be used with teenage athletes where appropriate.

Results need to be interpreted in the context of:

• Age
• Growth
• Body size
• Training experience
• Sport

Comparisons should not simply use adult values.

Testing may be useful for monitoring physical development over time.

Pre-season testing

Force plates can provide baseline measurements before a competitive season.

These may include:

• Jump height
• Power
• Force
• Side-to-side differences

Selected tests can later be repeated to assess how the athlete responds to pre-season or in-season training.

Baseline information may also be useful if an injury occurs later.

Performance screening

Force plate testing can form part of a wider performance screen.

The complete assessment may include:

• Strength testing
• Movement analysis
• Running
• Sprinting
• Jumping
• Mobility

Force plate data can add objective measurements to what is observed during these tasks.

The testing should answer a useful training question rather than simply produce as much data as possible.

Monitoring strength and conditioning

Force plates can help monitor how an athlete responds to a structured training programme.

For example, testing may be repeated after a period focused on:

• Strength
• Power
• Jumping

Changes in the data can help determine whether training is producing the intended physical adaptation.

Not every small change is meaningful, so results need to be interpreted over time.

Testing fatigue

Force plate results can vary when someone is fatigued.

This may be useful when monitoring athletes during demanding training periods.

However, performance can also vary because of:

• Sleep
• Recent competition
• Illness
• Motivation
• Normal day-to-day variation

One reduced test result does not automatically mean something is wrong.

Trends are generally more useful than a single number.

Symmetry between sides

Force plate systems often provide detailed comparisons between limbs.

This can be useful, particularly after injury.

However, complete symmetry is not always required.

An athlete may naturally have some difference between sides.

It is also possible for both sides to be equally weak.

For this reason, results should consider:

• Absolute performance
• Previous testing
• Sport
• Injury history

rather than focusing only on symmetry percentages.

What is a limb symmetry index?

A limb symmetry index compares performance between the two sides and expresses the difference as a percentage.

This can be useful during rehabilitation, but it has limitations.

If the uninjured side has become weaker during time away from sport, the injured side may appear relatively similar even though neither side has fully recovered.

Symmetry should therefore be considered alongside absolute strength and performance.

Force production versus movement quality

Force plates measure what happens between the body and the ground.

They do not show every detail of body movement.

For example, two athletes may produce similar force but use different:

• Knee positions
• Hip strategies
• Trunk movements

Video or clinical movement assessment may therefore be used alongside force plate data.

The combination provides a more complete picture.

Objective data and clinical judgement

Force plates can provide very precise numbers, but the presence of detailed data does not remove the need for clinical interpretation.

A result needs to be considered alongside:

• Symptoms
• Injury history
• Strength
• Training
• Movement
• Sport demands
• Confidence

The most useful question is not simply “Is this number normal?” but “What does this result mean for this person’s rehabilitation or performance?”

Force plate testing is not an injury predictor

Force plate testing can identify physical characteristics such as strength or landing asymmetry.

It cannot reliably predict exactly who will become injured.

Injury risk is influenced by many factors, including:

• Training exposure
• Previous injury
• Contact
• Fatigue
• Recovery
• Sporting situations

Testing is more useful for measuring qualities that can then be trained.

Turning results into rehabilitation

The value of testing comes from using the findings to guide the next stage.

For example, reduced force on one side may lead to additional:

• Single-leg strengthening
• Quadriceps training
• Calf strengthening
• Jump work

Reduced landing control may lead to:

• Landing practice
• Plyometric training
• Deceleration work

The programme should address the physical finding rather than simply repeat the test.

Turning results into strength and conditioning

For healthy athletes, testing may identify priorities such as:

• Increasing lower-body power
• Improving single-leg strength
• Improving repeated jump ability

A strength and conditioning programme can then be structured around these goals.

Re-testing can help measure whether the programme has produced meaningful change.

Re-testing

Force plate testing is particularly useful when measurements are repeated.

Re-testing may take place:

• After a rehabilitation block
• During return-to-sport progression
• After pre-season training
• During athletic development

Using similar testing conditions can make comparisons more meaningful.

Not every test needs to be repeated at every appointment.

How often should athletes be tested?

There is no standard frequency.

Testing should be completed when the results can influence:

• Training
• Rehabilitation
• Return-to-sport decisions

Some athletes may only need occasional baseline and follow-up testing.

Others within structured performance programmes may be tested more regularly.

What should I wear?

Wear comfortable exercise clothing that allows you to:

• Squat
• Jump
• Move freely

Suitable training shoes may be required depending on the test.

In some cases, testing may be completed barefoot if that is relevant to the protocol.

You will be advised if any specific preparation is needed.

Do I need to prepare?

For the most accurate performance testing, it may be useful to avoid unusually demanding training immediately before the assessment.

Recent fatigue can influence test results.

Your clinician may ask about:

• Training completed that day
• Previous day’s activity
• Current soreness
• Recent competition

This information helps interpret the results.

Is force plate testing safe?

Testing itself uses a non-invasive platform.

The main physical demand comes from the movement being performed.

For example, jump testing is only appropriate if you are physically ready to jump.

The clinician should select tests according to:

• Injury stage
• Strength
• Medical restrictions
• Current physical ability

Advanced testing should not be used before appropriate rehabilitation has been completed.

When testing may not yet be appropriate

Force plate testing involving jumping or high force may need to be delayed if you have:

• Significant pain
• Major swelling
• Recent acute injury
• Significant weakness
• Inability to jump safely
• Medical or surgical restrictions

A lower-level assessment or continued rehabilitation may be more suitable initially.

When further assessment may be needed

Further clinical or medical assessment may be required if you experience:

• Severe or rapidly worsening pain
• Significant new swelling
• Repeated joint giving way
• New significant weakness
• Persistent numbness
• A new injury during testing or rehabilitation
• Concerns about surgical healing

These issues should be reviewed before advanced testing continues.

Testing based on your goals

Force plate testing should answer questions that are relevant to you.

Your goals may include:

• Returning to sport
• Comparing leg strength
• Improving jump performance
• Monitoring rehabilitation
• Preparing for a new sports season
• Measuring lower-body power
• Assessing landing
• Monitoring athletic development
• Guiding strength and conditioning

The testing protocol can then be selected around these priorities.

What happens after force plate testing?

After testing, the results can be explained in practical terms.

Recommendations may involve:

• Strengthening
• Power training
• Single-leg exercises
• Jumping
• Landing
• Plyometric training
• Further rehabilitation
• Return-to-sport progression

You may also have selected tests repeated later to monitor change.

The aim is to use the data to make rehabilitation or training more specific.

How many appointments will I need?

Some people may only require one force plate assessment.

Others may be tested at different stages of rehabilitation or training.

Further sessions may be useful when:

• Monitoring recovery after injury
• Reviewing return-to-sport readiness
• Measuring progress after strength training
• Comparing pre-season and later performance

The number of sessions depends on what the testing is being used to assess.