Tag: neck pain

Whiplash After a Car Accident: What a Whiplash Chiropractor in Meridian, Idaho Wants You to Know

A clear, whole-body plan for neck pain, headaches, and “I didn’t feel it at first” symptoms

Whiplash can look deceptively “minor” in the first hours after a crash—then the stiffness, headaches, shoulder tension, or dizziness show up later. That delayed onset is common, and it’s one reason people in the Treasure Valley often wait too long to get the right kind of evaluation and guidance. A whiplash chiropractor focuses on restoring healthy motion, reducing strain on irritated tissues, and rebuilding stability so the neck (and the rest of the body) can move normally again—without relying on rest alone.

What “whiplash” actually is (and why symptoms can spread)

Whiplash is a rapid back-and-forth (or multi-directional) motion of the head and neck that can strain muscles and ligaments, irritate joints, and sensitize the nervous system. While many people associate it only with rear-end collisions, the mechanism can happen in many types of crashes—and even in sports impacts.

Symptoms commonly include neck pain and stiffness, headaches, shoulder or upper-back pain, dizziness, and sometimes tingling or unusual sensations into the arm. Importantly, pain and stiffness may not start immediately; they can take hours to days (and in some cases longer) to fully show up. That’s why “I feel okay” at the scene doesn’t always mean “I’m fine.”

Subtle signs people in Meridian often dismiss

Not every whiplash case looks dramatic. Some of the most disruptive cases start with small changes like:

• Headaches that weren’t there before (especially base-of-skull or temple headaches)
• Stiffness when turning your head to check mirrors
• Shoulder tightness or a “knot” that keeps returning
• Dizziness, “off-balance” sensations, or trouble concentrating
• Jaw tension or facial tightness that appears alongside neck pain

If symptoms are escalating, spreading, or interfering with sleep, work, or driving, that’s a strong signal to get assessed.

When to seek urgent medical care

Chiropractic and physiotherapy-style rehab can be very helpful for many people—but urgent medical evaluation matters if you have red flags such as:

• Severe or worsening headache, fainting, confusion, or new neurological symptoms
• Weakness, numbness that’s progressing, or trouble walking
• Severe neck pain after a high-force collision or direct head impact
• Chest pain, shortness of breath, or symptoms you can’t explain

If you’re unsure, it’s appropriate to start with an urgent care or ER evaluation—then follow up for conservative musculoskeletal care as recommended.

Quick “Did you know?” facts

Delayed symptoms are common
Neck pain and stiffness can start hours to days after an accident, not always at the scene.
Headaches often come with whiplash
Many whiplash cases include headaches along with neck pain and upper-back tightness.
Movement matters (when appropriate)
For many people, returning to gentle activity and guided exercise can support recovery better than prolonged rest.

What a whiplash chiropractor may evaluate (beyond “Does it hurt?”)

A quality whiplash-focused visit typically looks at how your entire system is responding—not just where pain is loudest. At Boise Apex Chiropractic & Wellness, a whole-body approach may include:

• Range of motion (turning, tilting, and controlled movement) and how symptoms change with motion
• Joint function in the cervical and thoracic spine (neck and upper back), and sometimes shoulders
• Muscle tone and protective spasm (what’s tightened to “guard” the area)
• Posture and movement patterns that can keep symptoms cycling
• Neurological screening to help identify when additional medical evaluation is warranted

The goal is to identify what’s limiting recovery—then choose care that matches your phase: relief, corrective, and longer-term wellness.

Step-by-step: smart early habits for whiplash recovery

The first few weeks are often when people unknowingly create patterns that make symptoms linger. Here’s a practical roadmap that aligns with conservative care best practices and what we commonly see after car accidents.

1) Get checked—even if symptoms are “not that bad”

Delayed pain is common. An early assessment can document your baseline, screen for red flags, and give you a plan that prevents excessive guarding and stiffness from setting in.

2) Use comfort strategies without “shutting down” movement

Many people do best with a balance: short bouts of rest, comfortable positions, and gentle motion breaks. Prolonged stillness can increase stiffness and make returning to normal activity harder.

3) Rebuild control: mobility first, then stability

Early on, the neck often loses smooth, confident motion. Once pain is calmer, targeted strengthening (often paired with upper-back and shoulder work) helps the neck stop “bracing” all day. This is where physiotherapy-style rehab can be a major difference-maker.

4) Watch the “workday whiplash” traps

A crash is the trigger, but daily habits can keep symptoms alive: long laptop sessions, cradling the phone, driving with tense shoulders, or sleeping with an awkward pillow setup. Small posture and ergonomic changes often reduce flare-ups quickly.

5) Don’t ignore dizziness or concentration changes

These can occur with whiplash and deserve thoughtful assessment. Sometimes the neck’s proprioception (your body’s position-sensing system) is disrupted; other times additional evaluation is appropriate. If dizziness is severe, worsening, or paired with neurological symptoms, seek medical care promptly.

Optional comparison table: common approaches after whiplash

Approach Best fit What it can help with Notes
Chiropractic adjustments (when appropriate) Joint stiffness, movement restriction, mechanical neck/upper-back pain Mobility, pain modulation, restoring joint motion Care should be individualized and paired with rehab when needed
Physiotherapy-style rehab Persistent tightness, weakness, recurrent flare-ups, posture strain Stability, strength, endurance, movement retraining Often key for long-term resilience and prevention
Massage therapy Muscle guarding, stress-related tightness, headaches linked to tension Comfort, circulation, reduced muscle tone Most effective when combined with movement-based care
Nutrition support People who want whole-body recovery habits Energy, sleep support, healthy inflammation balance, tissue repair support Not a “quick fix,” but helpful for long-term wellness

Local angle: whiplash care for Meridian, Idaho drivers

If you live in Meridian, you’re likely commuting between home, school activities, and Boise-area work. That means more time in the car—and more stress on the neck after an accident because driving requires frequent head turns, shoulder checks, and sustained posture.

A practical Meridian-focused recovery goal isn’t just “less pain.” It’s being able to:

• Turn your head comfortably to merge and change lanes
• Sit through a full workday without escalating symptoms
• Sleep through the night without waking up stiff and guarded
• Return to gym routines, yardwork, and family activities confidently

When care is personalized—combining chiropractic, physiotherapy-style rehab, and supportive therapies—patients often feel more in control of the recovery process.

Ready to talk with a whiplash chiropractor?

If you’ve had a car accident and you’re noticing neck pain, headaches, stiffness, or dizziness, an evaluation can help clarify what’s going on and what type of conservative care fits your situation.
Book Your Visit

Tip: If your symptoms started days after the crash, that still counts—bring notes on when each symptom began and what makes it better or worse.

FAQ: Whiplash chiropractic care in Meridian

How soon should I see a whiplash chiropractor after a car accident?

If you have neck pain, headaches, stiffness, dizziness, or symptoms that are developing after the crash, it’s reasonable to schedule an evaluation promptly. Early guidance can help you avoid compensations that make recovery slower.

What if my pain didn’t start until a few days later?

That pattern is common with whiplash. Track the onset (day and time if you can), what movements aggravate it, and whether headaches, shoulder tightness, or dizziness appeared as well.

Will I need X-rays or imaging?

Not everyone needs imaging. A clinician typically decides based on your history, exam findings, and any red flags. If there’s concern for more serious injury, you may be referred for medical imaging.

Is it normal to have headaches with whiplash?

Yes—headaches often occur alongside neck strain and joint irritation. Many people notice base-of-skull tension headaches that flare with prolonged sitting, screens, or driving.

What’s the difference between “relief care” and “corrective care”?

Relief care focuses on calming pain and restoring comfortable motion. Corrective care is more about rebuilding stability, posture, and movement capacity so symptoms are less likely to return under everyday stress.

Can massage help whiplash?

Massage can be very helpful for muscle guarding and stress-driven tightness, especially when paired with a movement plan (mobility and strengthening) and targeted chiropractic/physiotherapy care.

Do you treat people from Meridian even though you’re in the Boise area?

Yes. Many patients travel from Meridian and across the Treasure Valley for a multidisciplinary, whole-body approach that includes chiropractic, physiotherapy-style rehab, nutrition support, and massage therapy.

Glossary (plain-English)

Whiplash-associated disorder (WAD)
A term used to describe the cluster of symptoms that can happen after a whiplash mechanism—neck pain, stiffness, headaches, dizziness, and more.
Range of motion
How far and how smoothly you can move your neck in different directions without pain or restriction.
Muscle guarding
A protective tightening response after injury. It can help short-term, but if it persists it often feeds stiffness and headaches.
Proprioception
Your body’s internal “position sense.” When it’s disrupted, people may feel off-balance or less confident with movement.
Cervicogenic headache
A headache driven by neck structures (joints, muscles, posture). It often flares with neck movement or prolonged sitting.

Whiplash After a Car Accident: When to See a Whiplash Chiropractor in Boise (and What to Do First)

A practical, whole-body plan for neck pain, headaches, and stiffness after a crash

Even a “minor” rear-end collision can leave you with symptoms that show up hours—or days—later. Whiplash (often described as a neck sprain/strain from rapid acceleration-deceleration) can affect more than your neck: it may trigger headaches, shoulder tightness, jaw tension, dizziness, sleep disruption, or a feeling that your upper back just won’t loosen up. Many people improve within a few weeks with an appropriate plan, but the early steps matter—especially if your symptoms are escalating, spreading, or interfering with work and daily life.

What whiplash actually is (and why it can feel “all over”)

Whiplash is commonly associated with rear-end impacts, but it can happen in many crash types. The rapid back-and-forth motion can strain muscles and tendons and stress ligaments around the cervical spine (neck). It can also irritate joints, change normal motion patterns, and create protective muscle guarding—your body’s way of trying to stabilize the area.

Because the neck connects to the upper back, ribs, shoulders, and jaw—and because nerves travel from the neck into the arms—symptoms can “refer” or spread. That’s why a whiplash chiropractor often evaluates not only the neck, but also posture, shoulder mechanics, upper-back mobility, breathing mechanics, and any numbness/tingling patterns.

Common whiplash symptoms (and what “delayed onset” can look like)

Some people feel neck pain immediately. Others feel “fine” at first and then notice symptoms 24–72 hours later as inflammation and muscle guarding build. Common symptoms include:
Symptom What it may feel like day-to-day Why it matters
Neck stiffness/soreness Hard to turn your head, worse after sitting or driving Often improves with guided mobility and tissue work once serious injury is ruled out
Headaches Base-of-skull pressure, “band” headache, or behind-the-eye ache May relate to neck joint irritation, muscle tension, or posture changes
Shoulder/upper-back tightness Traps “locked up,” pain between shoulder blades A whole-body plan often needs upper-back + rib mobility, not just neck work
Tingling or radiating symptoms Pins/needles into arm or hand, grip weakness, heavy arm Requires careful evaluation; can indicate nerve irritation
Dizziness, nausea, fogginess Unsteady feeling, motion sensitivity, fatigue May require medical evaluation for concussion or other concerns
Note: This is general education, not a diagnosis. If you have severe symptoms, worsening neurological signs, or concerns for concussion, seek urgent medical care.

When to see a whiplash chiropractor vs. when to go to urgent care/ER

A whiplash chiropractor can be a great next step for many people once urgent red flags are ruled out—especially if you’re dealing with stiffness, postural strain, headaches, or restricted movement after a collision.

Seek urgent medical evaluation first if you have:
severe or rapidly worsening neck pain; loss of strength; numbness that’s spreading; trouble walking or coordination issues; loss of bladder/bowel control; fainting; severe headache unlike your usual; repeated vomiting; confusion; slurred speech; or any concern for head injury/concussion.

If your symptoms are moderate, stable, and mainly mechanical (stiffness, limited motion, muscle spasm, headaches that feel linked to neck tension), a chiropractor and physiotherapy team can typically focus on restoring motion and function with a measured approach.

What a comprehensive whiplash plan often includes

At Boise Apex Chiropractic & Wellness, care is built around a whole-body approach and appropriate pacing—relief, corrective, and long-term wellness phases—so you’re not just “chasing symptoms.”

1) Smart assessment and safety screening

A careful history and exam helps identify patterns consistent with soft tissue sprain/strain versus signs that warrant imaging or referral. Your provider may also check posture, range of motion, neurological indicators, and shoulder/upper-back mechanics.

2) Gentle chiropractic care (when appropriate)

Chiropractic adjustments may be used to support joint motion in the neck and upper back. Technique choice matters after a collision—many clinics tailor the approach (for example, instrument-assisted or low-force methods) based on irritability, mobility limits, and your comfort.

3) Physiotherapy: mobility + stability + retraining

Evidence-informed guidance for cervical sprain/strain often emphasizes returning to safe movement (after ruling out serious injury) rather than prolonged rest. Physiotherapy may include targeted stretching, strengthening, traction when indicated, posture retraining, and a home program that matches your stage of healing.

4) Supportive therapies for the “tight and guarded” phase

Massage therapy and soft tissue techniques can be helpful for muscle guarding in the neck/upper back, while nutrition support can complement recovery by supporting sleep, inflammation management, and steady energy—especially when stress is high.

Step-by-step: what to do in the first 7–14 days after a crash

Quick priority:
Rule out red flags first. Then focus on calm, consistent movement and a plan that restores function without repeatedly flaring symptoms.

Step 1: Document your symptoms (even if they’re mild)

Write down when symptoms started, what worsens them (driving, computer work, sleeping position), and whether anything radiates into the arms. Delayed onset is common, so a timeline helps your provider tailor care and monitor progress.

Step 2: Keep movement “easy and frequent”

Gentle, pain-limited range-of-motion movements throughout the day often beat long periods of stillness. Aim for short movement breaks during desk work and driving. If you’re unsure what’s safe, get examined before starting any new routine.

Step 3: Reduce “stacking stress” (sleep, hydration, and screen posture)

Early recovery can be derailed by poor sleep and long hours in forward-head posture. Keep screens at eye level, use a supportive pillow setup, and avoid long drives without breaks when possible.

Step 4: Get evaluated if symptoms last more than a few days—or interfere with life

If stiffness, headaches, or shoulder/upper-back pain are limiting your daily activities, an exam can identify whether you’re dealing with primarily joint restriction, muscle guarding, nerve irritation, or compensations that need active rehab.

Boise-specific considerations: commutes, recreation, and “desk-neck” overlap

In Boise, a lot of people blend desk work with active weekends—Greenbelt walks, foothills hikes, cycling, skiing trips, and long drives across the Treasure Valley. Whiplash often shows up most during:

• Longer commutes and stop-and-go traffic (sustained neck posture)
• Laptop-heavy workdays (forward-head posture increases strain)
• Early return to workouts without a progression plan (flare-ups)

A good local care plan helps you return to driving, lifting, and recreation with graded steps—so you’re not stuck in a loop of “feel better, do too much, flare up again.”

Ready to get checked by a whiplash chiropractor in Boise?

If you’re dealing with neck stiffness, headaches, shoulder tightness, or limited motion after a car accident, our team can help you understand what’s going on and build a plan that fits your body and your goals.

FAQ: Whiplash chiropractic care in Boise

How soon after a car accident should I see a whiplash chiropractor?
If you have red flags (severe symptoms, neurological changes, or concussion concerns), get urgent medical evaluation first. Otherwise, many people benefit from an evaluation within the first week—especially if stiffness, headaches, or limited motion are building over a few days.
Why does my neck hurt more two days after the crash?
Delayed onset can happen as inflammation increases and muscles guard to protect irritated tissues. It’s common to feel stiffer 24–72 hours later, which is one reason documenting your timeline is helpful.
Will I need imaging (X-ray or MRI) for whiplash?
Not always. Imaging decisions depend on your symptoms, exam findings, and clinical decision rules. If there are signs of serious injury or neurological involvement, your provider may recommend imaging or refer you for medical evaluation.
What’s the difference between chiropractic care and physiotherapy for whiplash?
Chiropractic care often focuses on restoring joint motion and reducing mechanical irritation, while physiotherapy emphasizes movement retraining, strength, flexibility, and functional progression. Many people do best with a coordinated plan that blends both.
Can whiplash cause headaches?
Yes. Headaches can be related to neck joint irritation, muscle tension near the base of the skull, postural changes, or sleep disruption after the crash. An exam helps clarify likely drivers and the safest starting point.
I was in a rear-end collision and my low back hurts too. Is that still “whiplash”?
Whiplash typically refers to neck acceleration-deceleration strain, but crashes can strain multiple regions at once. It’s common to have combined neck, mid-back, and low-back irritation that needs a whole-spine movement and stability plan.

Glossary

Acceleration-deceleration injury
A rapid change in speed that causes the head and torso to move differently, stressing soft tissues and joints.
Cervical spine
The seven vertebrae in the neck region.
Muscle guarding
A protective tightening of muscles in response to pain or perceived instability.
Radicular symptoms
Pain, numbness, tingling, or weakness that may travel along a nerve pathway into the arm.
Range of motion (ROM)
How far and comfortably you can move a joint (like turning or tilting your head).
Looking for more about our clinic? Visit About Boise Apex Chiropractic & Wellness.

Whiplash Chiropractor in Boise: Symptoms, Timelines, and What Helps You Recover Safely

If your neck feels “off” after a car accident, it’s worth taking seriously

Whiplash is one of the most common injuries after a rear-end or side-impact collision. It can show up as neck pain, stiffness, headaches, shoulder tension, dizziness, or a feeling like you “can’t get comfortable.” At Boise Apex Chiropractic & Wellness, we take a whole-body approach—looking at the neck, upper back, nervous system, posture, and the supporting muscles that help you move confidently again.

What “whiplash” actually means (and why symptoms can be delayed)

Whiplash is commonly used to describe an injury from a rapid acceleration–deceleration force to the neck—often in motor vehicle collisions. That quick motion can irritate joints, strain muscles and ligaments, and sensitize nerves. The Quebec Task Force described whiplash-associated disorders (WAD) as a spectrum of issues that can follow this mechanism, from pain without clear physical findings to more severe presentations. (pmc.ncbi.nlm.nih.gov)

One reason whiplash can be confusing is that symptoms may not fully appear right away. Many people feel “shaken up” the day of the crash and notice worsening stiffness or headaches over the next 24–72 hours as inflammation, muscle guarding, and stress responses ramp up.

Common whiplash symptoms (and what they can feel like day-to-day)

  • Neck pain and stiffness (especially turning your head to check blind spots)
  • Headaches (often starting at the base of the skull)
  • Shoulder/upper back tightness or burning between the shoulder blades
  • Reduced range of motion or a “locked up” feeling
  • Dizziness or feeling off-balance
  • Jaw tension or facial tightness
  • Tingling, numbness, or weakness into an arm/hand (needs prompt evaluation)
  • Sleep disruption because you can’t find a comfortable position

Important: If you have severe headache, fainting, significant dizziness, trouble walking, new weakness/numbness, or symptoms after a significant trauma, seek urgent medical evaluation right away.

Whiplash severity: a simple way clinicians describe WAD grades

Providers may reference the Quebec Task Force (QTF) WAD grading system. This isn’t a “label” meant to scare you—it’s a way to communicate what’s present and what needs attention. (sira.nsw.gov.au)

WAD Grade What it typically includes Why it matters
I Neck complaint (pain, stiffness, tenderness) without clear physical signs Often responds well to timely, active care and guided movement
II Neck complaint + musculoskeletal signs (e.g., reduced range of motion, tenderness) May benefit from a combined approach (joint + muscle + posture rehab)
III Neck complaint + neurological signs (e.g., sensory changes, weakness, reflex changes) Requires prompt, careful evaluation and appropriate referral when indicated
IV Neck complaint + fracture or dislocation Medical emergency and imaging/medical management are priorities

How long does whiplash take to heal?

Recovery time varies widely. Some people improve in days to a few weeks, while others have lingering pain, headaches, or reduced tolerance for activity. Your timeline often depends on factors like the force of impact, prior neck issues, stress/sleep disruption, movement fear-avoidance, and whether care focuses on restoring normal motion and strength early on.

A practical “week-by-week” pattern many people recognize

  • Days 1–3: soreness, stiffness, headache, and muscle guarding often increase as inflammation sets in.
  • Weeks 1–3: targeted movement, gentle mobility, and guided strengthening can help restore confidence and range of motion.
  • Weeks 3–8: many patients focus on rebuilding endurance (work posture, driving tolerance, sleep positioning, lifting mechanics).
  • Beyond 8 weeks: if symptoms persist, it’s worth reassessing triggers, biomechanics, and contributing issues (upper back, rib mobility, jaw, stress load, vestibular symptoms, etc.).

Evidence-based resources commonly emphasize staying active within tolerance and using a plan that progresses you back to normal movement rather than relying only on rest. Mayo Clinic also notes that stretching and movement exercises and, when needed, physical therapy may help reduce ongoing pain and support function. (mayoclinic.org)

Step-by-step: What to do after a car accident when you suspect whiplash

1) Get checked for red flags first

If you have severe pain, new neurological symptoms (numbness/weakness), trouble walking, or symptoms after significant trauma, seek urgent medical evaluation. For neck pain after an injury, MedlinePlus advises contacting a healthcare provider—especially if you can’t move an arm/hand or the injury was from a fall or blow. (medlineplus.gov)

2) Use short-term symptom relief—without “shutting down” movement

Many people do well with short periods of ice/heat, gentle range-of-motion work, and appropriate over-the-counter options when medically safe. Whiplash resources commonly include these home-care strategies alongside a plan to regain normal function. (healthline.com)

3) Prioritize gentle mobility + progressive strengthening

Early on, many patients benefit from restoring comfortable motion (not forcing painful end ranges). As symptoms calm, strengthening the deep neck flexors, upper back muscles, and postural stabilizers can help reduce “recurring flare-ups” during work, driving, and sleep.

4) Choose care that matches your phase: relief, corrective, then wellness

At Boise Apex Chiropractic & Wellness, many whiplash care plans follow a sensible progression: calm pain and irritation, restore motion and joint mechanics, then build durable strength and habits so you can stay active long-term. A multidisciplinary approach (chiropractic care, physiotherapy-style rehab, massage therapy, and nutrition support when inflammation/stress are factors) can be especially helpful for whole-body recovery.

Did you know? Quick facts that matter after a collision

Seat belts reduce serious crash-related injuries and deaths by about half. Proper belt fit matters—snug lap belt across the hips/pelvis and shoulder belt across the chest, away from the neck. (cdc.gov)

Soft collars aren’t the default anymore. They were once common, but many modern recommendations emphasize guided movement and rehab to restore function (collars may be used selectively when a clinician recommends them). (mayoclinic.org)

The Boise angle: why whiplash can linger here (and what helps)

In Boise, many people spend time commuting, traveling the connector, or driving between work, school, and outdoor activities. After a whiplash injury, the combination of driving posture (head forward, shoulders tight) and screen time can keep the neck irritated—even when the original injury is improving.

Helpful local habit shifts include: adjusting headrest height, taking brief “posture resets” between meetings, and building neck/upper-back endurance so you can handle long drives to the foothills or weekend trips without flare-ups.

Ready to talk with a whiplash chiropractor in Boise?

If you’ve had a car accident and your neck, headaches, or upper back still don’t feel right, a targeted evaluation can help you understand what’s driving symptoms—and what to do next.

Schedule an Appointment

What to bring: accident date, symptom notes (what worsens/helps), and any imaging or ER paperwork (if you have it).

FAQ: Whiplash chiropractic care in Boise

Should I wait a few days to see if whiplash goes away?

If symptoms are mild, some people improve quickly. Still, if your symptoms started after an accident, it’s smart to get evaluated—especially if pain is increasing, you’re getting headaches, or you’re limiting normal activity. Mayo Clinic recommends seeing a healthcare professional as soon as possible after injury-related symptoms. (mayoclinic.org)

What’s the difference between “neck strain” and whiplash?

People often use the terms interchangeably. Clinically, whiplash describes the mechanism (rapid force to the neck) and “WAD” describes the symptoms and findings that can follow. (pmc.ncbi.nlm.nih.gov)

Can whiplash cause headaches?

Yes. Headaches are common after neck injuries and may be related to irritated joints, muscle tension, or referred pain patterns from the upper cervical region.

Is rest better than movement for whiplash?

Short-term rest can help during the most painful phase, but many guidance sources emphasize returning to comfortable movement and rebuilding function with progressive exercises rather than prolonged immobilization. (mayoclinic.org)

When should I be concerned about arm tingling or numbness?

If you notice new numbness, tingling, or weakness—especially after an accident—get evaluated promptly. These signs may indicate nerve involvement and require a careful exam and, in some cases, additional testing.

Glossary (helpful terms)

Whiplash-associated disorders (WAD): A classification for symptoms and signs that can occur after an acceleration–deceleration injury to the neck. (sira.nsw.gov.au)

Range of motion (ROM): How far and comfortably a joint (like your neck) can move in each direction.

Neurological signs: Findings like numbness, tingling, weakness, or reflex changes that may suggest nerve involvement.

Acceleration–deceleration: The rapid change in speed that can transfer force through the body in a collision. (pmc.ncbi.nlm.nih.gov)