Street Cred: Endurance Running Biomechanics

Transcription

1 Endurance Running Biomechanics Sound Running Principles Lisa M Duncan, PT, ATC, and USAT Certified coach Bob Duncan BA USAT Certified Coach Street Cred: Lisa Duncan: PT ATC since Has completed 3 IM races, including World Championships in Kona. Has competed with Team USA at long course World Championships in Sater Sweden, finishing 4th. Is Certified USAT Coach. Bob Duncan: BA, USAT Certified coach. Has completed 6 IM races. Coached 4 IM World Championship qualifiers (6 total finishes), 3 age group USAT long course champions. Current coach of USAT #1 ranked year old male triathlete. And lots of other stuff. Overview Three Biomechanical Assessments Running Drills Nutshell Checklist Clinical Assessment Key Muscle Groups Static Drills>>Dynamic Warm Ups A Word about Barefoot Running What does good running form look like? - tall torso, slight FORWARD LEAN of torso, and minimal arch in low back (neutral spine) Lean occurs at ankles and eyes will look approximately 35 feet ahead - ROTATION should be controlled, via the core. Some rotation is necessary to maintain relaxed form, particularly through the shoulders. Too much will pull you off line. What does good running form look like, cont -ARMS move forward and back, but do not cross midline. ELBOWS are held at 90 degrees or less. Elbow driving rearward is the focus. - KNEES drive forward, lifting the thigh to about 45 degrees. The trailing leg NEVER FULLY EXTENDS at the knee. What does good running form look like, cont -TOUCHDOWN occurs nearly directly under the body from any view. (questionable re: WBOS vs NBOS and effect on CPD, Hip add, knee valgum) It can be rearfoot (heel), midfoot, or ball of foot. Tibia should be nearly vertical at contact. Goal is minimal braking force, and a springy interaction with the surface. -CADENCE should be about 180 steps per minute. Count 1 leg for 15 seconds and multiply x 4, goal of 90 per leg. Increase cadence via lean and mechanics, NOT just turnover. 1

2 Now with a little bit of the science... Push Off involves ankle extension and uses gastroc/soleus. Rear leg never fully extends. Push is FORWARD. Knee Drive is also forward, not upward, thigh to about 45 degrees. Uses hip flexors and lower abs. The tibia and foot should not swing forward until the thigh is at this point. Paw Back occurs when the leg is moving backward as it makes contact, tibia near vertical. Uses HS and gluteals. (overstriding = heel strike= excessive loading forces are not absorbed by the achilles and are therefore transmitted upward through the leg and body!) Three critical biomechanical assessments Our goal is to improve running economy and prevent injury so that runners can overload and recover. Fast runners with poor mechanics Slow runners with great mechanics ie most runners want to go faster with less effort/injury! Assess the runner for: Forward lean Arm position Foot contact/touchdown Bonus: cadence Forward Lean Drills Drills can build onto each other, ie this is a block for future drills. Video clips Cues fingertips to wall, or use buddy neutral spine (core work is critical here) lean from ankles Eyes forward (not down!) Buddy break aways Tethered drills, tire drills, power cords Arm Carriage Drills Video Clips Cues Hold a bean in fold Hand stays above iliac crest Elbow drives rearward DLS, Stride stance, SLS What do we know about footstrike? 1. FFS demonstrate lower patellofemoral contact forces and stresses compared with heel strikers. 2. Knee frontal plane moment is lower in the FFS (Think OA/DJD prevention) 3. FFS demonstrate higher plantarflexor moment and Achilles tendon force compared w RFS (Achilles tendinopathy, plantar fasciitis, metatarsal stress fx). 4. Trend toward higher cadence w FFS. Foot Contact Drills Video Clips Cues Springy interaction with surface Ankling Hovering Skipping Might need a cadence adjustment to fix 2

3 CADENCE Running Step Rate should be 90 contacts/foot/minute. <90 = increased risk of injury. >90= increased activity in glute max and medius, decreased activity of anterior tib. (all in late swing) > 90 = decreased hip adduction/cpd. Change this via drills: address the 3 critical movement errors!! Running at an increased step rate may serve as therapeutic exercise! Nutshell checklist: Front and Rear views Arms do not cross midline, elbows at 90 degrees min Watch for shoulder and pelvis rotation: excessive (needs core) or limited (needs arm drills?) Pelvis should stay fairly level Knees drive forward, no scissoring Foot should land directly under head Maybe not? WBOS study From back can watch feet for Excessive pronation/supination Crossing midline (ie NBOS) Nutshell checklist: Side views Forward lean, eyes forward not down Hands stay above iliac crest and elbow (90 deg) drives rearward Running clips: notice forward lean, arm position, and foot contact Thigh should drive to about 45 degrees. Foot should land directly under COG, with leg moving backward as it makes contact Knee should never fully extend Limited up and down motion (2-3 inches) Ankle should move through large ROM Okay, I got 5/5 in all MMT's. Now what? Functional Assessment in the clinic might include toe walking, heel walking, squats, DL jumps, SL squats, SL hops, ability to hip hike, hops for distance. Can add raised surface for more challenge. Multisegmental flexion, extension, and rotation. Functional Movement Screen, part or all. If all else fails, hone in on sagittal plane. At the CORE of the matter Role of the core Rectus ab and erector spinae keeps neutral spine and erect torso Obliques eccentrically contract at midstance thru preswing to control ipsilateral pelvic rotation TA, multifidus and QL provide segmental stability/neutral spine Assess q&d via crossed arms at torso, and lack of control of transverse plane motion Is it easier to jump into the lake from the canoe or the dock? 3

4 At the CORE of the matter Core Routine: Quad Alt UE/LE, with/without ball, toe sllders if necc. Front planks Swiss Ball prone planks Swiss ball walkouts to double knee to chest; walkouts to pike Isom. Torso rotation Side planks with pelvic lowering, or hip abd But what about the butt... Gluteus Medius Role: Eccentrically controls contralateral hip drop. Controls femoral IR at loading and midstance, then concentrically assists with ER from midstance to preswing. Delayed onset and decreased duration of glute med activity = CPD/Hip add Bang for the buck... Sidelying hip abd: clam shell, at the wall Sideplanks Single leg squats, single leg deadlifts Monster band walks, sideways Can the static glute med drill transfer to running?? 1. Single leg squat progressions: can train to decrease hip adduction, hip internal rotation, and CPD, but what of the carryover to running? 2. Running with a mirror: verbal cues only with good outcomes in a case study. Again, the improved running can become the therapeutic exercise! 3.Yes, this is a critical movement error but if you address the other 3-4 issues, this will resolve, at least to some extent. And the rest of the butt? Gluteus Maximus Role:In swing eccentrically controls hip flexion, and in stance eccentrically controls lowering of center of mass with quads. Also eccentrically assists in controlling femoral IR at loading response to midstance. Concentrically pulls femur into extension through stance phase. Bang for the buck... Quad alt UE/LE (resist LE x 5 sec) Prone trunk ext, LE stab (use ball?) SL squat, SL deadlift Monster band walks: sideways, retro, 90 deg turn outs Why the sore quads? Quads co-contract with HS and glutes for limb stabilization at initial contact. Then begin to eccentrically control knee flexion moving into midstance. At swing phase quads concentrically extend the knee near end swing. Bang for the buck Medial step down Forward lunge, and variations Squats, DL, SL, on Bosu, with power cord How 'bout those hammies? The HS are the underpaid overworker. At terminal swing HS eccentrically controls tibia forward momentum. At IC they assist Quads and glutes in limb stabilization. Then HS eccentrically controls tibial IR through midstance. Shift moves toward concentric to drive femur into extension in late stance. Lastly in early to mid swing HS assists glute max in eccentrically controlling hip flexion. Bang for the Buck SLS with forward reach, superman, touches Sumo squats, broad jumps, box jumps Swiss ball bridges, HS curls 4

5 Jet Propulsion: Gastroc Soleus Ignited The Gastroc (type I fibers) primary function is concentric push off. Secondarily, it assists soleus in eccentrically controlling tibial forward momentum. The Soleus (type II fibers) primary function is eccentrically controlling tibial forward momentum. Bang for the buck Straight and Bent Leg heel raises, off step. SLS with forward reach, consider tband resist THINK... running is dynamic, exercises are static. Hmm... Once the exercise is mastered, consider ways to make it dynamic. What does the runner do well? What could they do better? Consider adding in the running drills (ankling, hovering, skipping) in a controlled manner initially. Consider putting variations in. Or teasing parts out. Warm Ups /Cool Downs? Dynamic vs. Static Running specific Achilles/calf: heel raises, toe and heel walk, ankling/hovering/skipping Knee flexion/quads: squat stretch, butt kicks Hip flexion/gluteals, HS: lunge walk, inchworms, skipping for height Hip extension/iliopsoas and lower abs: lunge walk, add OH reach, add rotation. Skipping for distance. Arms: swings and shoulder rolls Running Drills Can use the drills previously mentioned: ankling, hovering. Also skipping, lunges. More specific: Knee Drive Paw Back/sweep Barefoot? Skipping: height, distance, rotations For power, or endurance? Dynamic Warm Up Drills Workout Barefootin Barefoot populations What does barefoot running promote: Higher stride frequency/shorter stride length More knee flexion at foot strike leads to... Flatter foot placement at foot strike/ic Less time in stance More ankle ROM during stance Decreased peak plantar pressure under heel and increased peak plantar pressures under met heads Reduced VO2 cost? Barefootin Barefoot running will add strain to the achilles tendon as form accomodates. Build up gradually! Towel Curls Consider using this as a drill, on a turfed surface 5

6 Introducing Change Begin with drills Can begin static>> dynamic>>running, but not necc. Can use verbal feedback, gradually decreasing: run with your knees pointing forward, squeeze your buttocks, keep the bean in your elbow, etc Use visual feedback: mirrors, video. Increase distance gradually. Preferred pattern = least energy cost. Therefore... Common Injuries Roundtable Iliotibial Band Syndrome Plantar Fascitiis Achilles Tendonitis/Tendonosis Runner s Knee Shin Splints Hamstring Strain The motor learning must become habit to change the practice, and become the preferred pattern. Thank You! 6