Understanding Your Stride Rate During Your Runs

Stride Rate  What is it? Stride Rate is also known as your running cadence and is simply measured as the infamous acronym you've seen flying around: SPM, or steps per minute.

What should my stride rate be for each training run? Most importantly, before discussing SPM for different runs and speeds, it's important to make sure that regardless of number for your SPM, your hips are over your center of mass (or gravity) while you're running at your goal SPM! This way, you can eliminate overstriding aka getting plantar fasciitis and other potential hamstring injuries! Typically, recreational runners are told to run 150-180SPM and elite runners 180-200ish SPM. However, everyone is different. Therefore, everyone will have a different cadence that is the most optimal for THEM! Don't compare!  It's important to understand your own stride rate versus going off of arbitrary numbers. If the numbers that you're going for are not enabling you to eliminate overstriding, or the contrary while also jeopardizing your running form, you're setting yourself up for failure! You also could be putting WAY TOO MUCH WEIGHT ON YOUR HIPS/KNEES/ANKLE joints. Your stride rate is going to be different from Jimmy's stride rate because stride rate is determined by accounting for your personal height/weight/where you're at fitness wise/stride length. It is going to be different for everyone, even if it's a slight difference. Compare yourself to YOURSELF ONLY! It's a win win that way. What should I do if I need to adjust my stride rate? What if I don't know if I need to or not? If you feel that your form is off, let's get you a gait analysis session setup! If you KNOW it is off already, there are ways you can try to fix it without me! You can do this by manipulating your stride rate while making sure your feet are landing under your hips. To do this, you might need to increase your steps per minute. You can use a metronome to count how many steps per minute you're taking, OR you can manually do this by counting the steps you run in a minute by tracking each foot separately for example. This will allow you to get more accurate results by sticking to the SPM for one foot. Gives ya less to think about too! With your right foot, count the number of times it hits the ground in a minute.Then multiply that total number of steps by 2 to get the total steps taken by both feet in that given minute! Whatever speed you're at, you'll then know your steps per minute that you're running currently for that specific running speed. From there, you can then work on changing that up if needed! How can I adjust my own running cadence? To adjust your cadence to get it closer to that 180 spm mark for example (if that makes sense for you), you're going to need to have patience. DO NOT TRY TO DO THIS IN ONE DAY. It takes time! Slowly work on increasing your steps per minute by NO MORE than 5% between every 3 runs! Try doing these on your easy runs. It'll be easier to do this during them since you won't have to focus on hitting your workout paces, or focus on breathing, LITERALLY!  Can you explain why cadence should remain consistent, regardless of the speed that you're running? Your steps per minute aka your cadence SHOULD ALWAYS BE THE SAME, REGARDLESS OF THE TYPE OF RUN THAT YOU'RE DOING AND THE SPEED OF THE RUN THAT YOU'RE DOING! As you increase your speed, naturally, with good running form, you will feel and find that you're tending lean more forward from your ankles  and your stride length will naturally increase with the boost in acceleration and power that goes along with picking up your running speed. For easier and slower runs, eliminating the forward lean from your ankles (like you do at faster paces) and also the increased stride length that comes with ramping up with the speed, your gait, or your feet will be under your hips with a less forward lean. The same number of times each foot strikes to the ground per minute while your running should remain constant, regardless of the speed.  ___ Snippet from the article: "The biomechanics of running" from ScienceDirect that you might find interesting, as it relates to SPM (stride rate), but further elaborates on gait and the link between velocity and acceleration while increasing that running speed. Enjoy your new bedtime light reading! :) Gait  and  Posture  7  (1998)  77 – 95Review  PaperThe  biomechanics  of  runningTom  F.  NovacheckMotion  Analysis  Laboratory,Gillette  Children’s  Specialty  Healthcare,University  of  Minnesota,200E.Uni6ersity  A6e.,St.Paul,MN55101,USAReceived  25  August  1997;  accepted  22  September  1997AbstractThis  review  article  summarizes  the  current  literature  regarding  the  analysis  of  running  gait.  It  is  compared  to  walking  and sprinting.  The  current  state  of  knowledge  is  presented  as  it  fits  in  the  context  of  the  history  of  analysis  of  movement.  The characteristics  of  the  gait  cycle  and  its  relationship  to  potential  and  kinetic  energy  interactions  are  reviewed.  The  timing  of electromyographic  activity  is  provided.  Kinematic  and  kinetic  data  (including  center  of  pressure  measurements,  raw  force  plate data, joint moments, and joint powers) and the impact of changes in velocity on these findings is presented. The status of shoe wear literature, alterations in movement strategies, the role of biarticular muscles, and the springlike function of tendons are addressed.This  type  of  information  can  provide  insight  into  injury  mechanisms  and  training  strategies.  ©  1998  Elsevier  Science  B.V.Keywords:Running;  Biomechanics;  Kinematics;  Kinetics;  Electromyography;  Energy;  Injury1.  Introduction:historyTo   avoid   the   misconception   that   the   analysis   of running  is  a  new  area  of  interest,  one  need  only  examine  the  art  of  Grecian  vases  and  consider  the  writ-ings  of  Aristotle,  ‘Further,  the  forces  of  that  which causes  movement  and  of  that  which  remains  still  must be  made  equal...  For  just  as  the  pusher  pushes,  so  the pusher  is  pushed — i.e.  with  similar  force’  [1].  Leon-ardo  da  Vinci’s  interest  in  accuracy  in  painting  in  the15th   and   16th   centuries   increased   focus   on   human movement  and  was  followed  by  Newton’s  proclama-tion  of  his  three  laws  in  the  17th  century.  In  1836,  theWeber  brothers  (Wilhelm  and  Eduard)  set  the  agenda for  future  research  with  the  most  detailed  treatise  on walking   and   running   gait   to   date.   They   listed   150hypotheses  including  that  the  limb  can  act  as  a  pen-dulum.   More   sophisticated   tools   were   needed   than are  currently  available  to  test  them.  Etienne  JulesMarey  (1830 – 1904)  was  a  prolific  pioneer  of  instru-mentation.  He  was  among  the  first  to  employ  photog-raphy  and  use  it  as  a  true  photogrammetric  tool.  He Also  designed  and  built  the  first  serious  force  plat-form.  The  reader  is  referred  to  Cavanagh’s  historical review  [2]  for  further  insight  into  the  contributions and   historical   significance   of   the   works   of   Braune,Fischer,  Muybridge,  Hill,  Fenn,  Elftman,  and  Hubbard.The  explosion  of  interest  in  running  has  prompted a  comparable  explosion  of  research  and  assessment.This  has  been  potentiated  by  technical  advances  in-cluding   faster   cameras   and   marker   systems   which eliminate  the  need  to  hand  digitize  frame  after  frame of  video.  The  growth  of  this  field  has  been  spurred  by the  vast  growth  in  participation  in  distance  running  in the   late   1960’s   and   early   1970’s.   Approximately   30million  Americans  run  for  recreation  or  competition.The  rate  of  injury  is  significant.  Each  year  between1:4  and  1:2  of  runners  will  sustain  an  injury  that  is severe  enough  to  cause  a  change  in  practice  or  perfor-mance  [3,4].  This  may  lead  the  runner  to  seek  consul-tation,  alter  training,  or  use  medication.0966-6362:98:$19.00  ©  1998  Elsevier  Science  B.V.  All  rights  reserved.PIIS0966-6362(97)00038-6 [1][2][3,4] T.F.No6acheck:Gait  and  Posture7  (1998)  77 – 9578Because  running  shoe  companies  now  had  a  large new market, they spent part of their profits to support research.  The  increased  incidence  of  injury  highlighted the  lack  of  understanding  of  the  pathophysiology  and biomechanics of chronic running injuries. These injuries are   due   to   repetitive   application   of   relatively   small loads  over  many  repetitive  cycles  (in  sharp  distinction to  acute  traumatic  events  such  as  ACL  ruptures  in football — a  single  large  load).  The  tissues  respond  dif-ferently  as  well  [5 – 7].It is often the number of repetitions that is problem-atic.  A  variety  of  intrinsic  and  extrinsic  factors  have been  blamed  for  the  development  of  these  types  of injuries [3,4,8]. In addition, particular patterns of injury have been noted. James and Jones [8] noted that almost75%   of   complaints   fell   into   six   categories   (Fig.   1).Interestingly, one might intuitively think that particular anatomic  abnormalities  lead  to  specific  injury  patterns(e.g.   hyperpronation   predisposing   to   posterior   tibial syndrome   or   genu   varum   leading   to   iliotibial   band syndrome), but few such relationships have been found.Given  the  assumption  that  greater  understanding  will improve diagnosis and counseling, the quandary for the last  two  to  three  decades  has  been  how  to  make  more sense  out  of  why  and  how  injuries  occur.The  volume  of  literature  is  extensive;  therefore,  not all material can be reviewed or referenced. For the most part  this  treatment  of  the  topic  will  be  restricted  to biomechanics  and  its  application  to  the  study  of  run-ning  gait.  Clinical  information  will  be  reviewed  to  the extent  that  it  focuses  one’s  attention  on  the  issues  at hand.  The  reader  is  referred  to  articles  and  chapters dedicated  to  the  pathophysiology  and  management  of chronic  running  injuries  [3 – 7,9 – 14].  Running  Injuries[15] edited by Gary N. Guten, MD provides a relevant,recent  review  of  clinical  material.  These  clinical  and pathophysiological  issues  lie  outside  the  scope  of  this article.  Several  prior  review  articles  [16 – 21]  dedicated to the biomechanics of running gait are recommended.These  have  been  invaluable  to  this  author  over  the years  and  are  highly  recommended.  The  Biomechanics Of  Distance  Running  edited  by  Cavanagh  [22]  is  an essential  reference.Unfortunately,  a  significant  void  exists  between  the world  of  the  biomechanist  and  the  realm  of  the  clini-cian.  A  look  at  the  available  literature  reveals  that  the link  between  the  field  of  biomechanics  and  the  clinical realm  is  difficult  to  identify.  It  seems  that  Dr  StanJames  (Eugene,  OR,  USA)  has  been  the  clinician  who has  exhibited  the  greatest  understanding  of  the  biome-chanics  of  running  gait  [23].  He  has  also  used  biome-chanical insight to shed light on running injury patterns[8,24]   as   have   several   biomechanists   [25,26].   Even Though  shoe  manufacturers  have  lead  the  way  in  some areas   of   biomechanics   research,   one   must   wonder whether  a  broad  spectrum  of  focus  is  maintained  by that  approach.2.  Gait  cycleHow  does  one  go  from  a  standstill  to  maximum forward velocity during sprinting? How does the move-ment  strategy  change  between  walking  and  running locomotion?   The   demarcation   between   walking   and running  (Fig.  1,  point  A)  occurs  when  periods  of  dou-ble  support  during  the  stance  phase  of  the  gait  cycle(both   feet   are   simultaneously   in   contact   with   the ground) give way to two periods of double float at the beginning   and   the   end   of   the   swing   phase   of   gait(neither   foot   is   touching   the   ground).   Generally   as speed  increases  further,  initial  contact  changes  from being on the hindfoot to the forefoot (Fig. 1, point B).This  typically  marks  the  distinction  between  running and  sprinting.  In  practicality,  the  difference  between running  and  sprinting  is  in  the  goal  to  be  achieved.Running  is  performed  over  longer  distances,  for  en-durance,  and  with  primarily  aerobic  metabolism.  Jog-ging,    road    racing,    and    marathons    are    examples.Approximately  80%  of  distance  runners  are  rearfoot strikers.  Most  of  the  remainder  are  characterized  as midfoot  strikers  [27].  Sprinting  activities  are  done  over shorter  distances  and  at  faster  speeds,  with  the  goal  of covering  a  relatively  short  distance  in  the  shortest  pe-riod  of  time  possible  without  regard  for  maintaining aerobic metabolism. Elite sprinters perform with a fore-foot initial contact, and in fact, the hindfoot may never contact  the  ground.  For  sprinting,  the  body  and  its segments  are  moved  as  rapidly  as  possible  throughout the entire race. For distance running on the other hand,the body is moved at a more controlled rate in relation to  the  energy  demand  of  the  race.The gait cycle is the basic unit of measurement in gait analysis [28]. The gait cycle begins when one foot comes in  contact  with  the  ground  and  ends  when  the  same foot contacts the ground again. These moments in time are referred to as initial contact. Stance ends when the foot  is  no  longer  in  contact  with  the  ground.  Toe  off marks  the  beginning  of  the  swing  phase  of  the  gait cycle.  Each  of  these  phases  for  both  walking  and  run-ning is subdivided further as seen in Fig. 2. Because the stance  phase  in  walking  is  longer  than  50%  of  the  gait cycle,  there  are  two  periods  of  double  support  whenFig. 1. Forward human locomotion. At point A, stance phase equals50%  of  gait  cycle.  Periods  of  double  support  in  walking  give  way  to periods  of  double  float  in  running.  Point  B  for  the  purposes  of  the kinematic and kinetic sections of this article represents a change from hindfoot  to  forefoot  initial  contact. [5 – 7][3,4,8][8]Fig.   1[3 – 7,9 – 14][15][16 – 21][22][23][8,24][25,26]Fig.  1Fig. 1[27][28]Fig. 2 T.F.No6acheck:Gait  and  Posture7  (1998)  77 – 9579Fig.  2.  The  gait  cycle.  2a.  Walking  figure.  2b.  Walking  gait  cycle:  *IC,  initial  contact;  LR,  loading  response;  *TO,  toe  off;  MS,  midstance;  TS,terminal stance; PS, preswing; IS, initial swing; MS, midswing; TS, terminal swing. 2c. Running figure: 1. Stance phase absorption. 2. Stance phase generation.  3.  Swing  phase  generation.  4.  Swing  phase  reversal.  5.  Swing  phase  absorption.  *Musculoskeletal  animation  produced  using  SIMM(Software  for  Musculoskeletal  Modelling,  Musculographics,  Chicago,  Illinois).  2d.  Running  gait  cycle:  *for  running  and  sprinting;  IC,  initial contact;  TO,  toe  off;  StR,  stance  phase  reversal;  SwR,  swing  phase  reversal;  absorption,  from  SwR  through  IC  to  StR;  generation,  from  StRthrough  TO  to  SwR.both  feet  are  on  the  ground  (Fig.  3),  one  at  the  begin-ning  and  one  at  the  end  of  stance  phase.In  running,  toe  off  occurs  before  50%  of  the  gait cycle is completed. There are no periods when both feet are  in  contact  with  the  ground.  Instead,  both  feet  are airborne  twice  during  the  gait  cycle,  one  at  the  begin-ning and one at the end of swing [30,31], referred to as double  float.  The  timing  of  toe  off  depends  on  speed.Less time is spent in stance as the athlete moves faster.In our study, toe off occurred at 39 and 36% of the gait cycle  for  running  and  sprinting,  respectively.  Faster Runners  and  elite  sprinters  spend  much  less  time  instance  than  that  (Fig.  3).  World  class  sprinters  toe  off as  early  as  22%  of  the  gait  cycle  [32].Regardless of speed, alternate periods of acceleration and  deceleration  occur  during  running  referred  to  as absorption  and  generation  (Fig.  2c,d).  As  can  be  seen,these  phases  do  not  coincide  with  the  timing  of  initial contact and toe off. They are out of phase. During the period  of  absorption,  the  body’s  center  of  mass  falls from its peak height during double float. This period is divided by initial contact (IC) into swing phase absorp-tion (Fig. 2c,c5) and stance phase absorption (Fig. 2cc1).  The  velocity  of  the  center  of  mass  accelerates horizontally  during  this  period  as  well.  After  stancephase  reversal,  the  center  of  mass  is  propelled  upward and  forward  during  stance  phase  generation  (Fig.  2cc2). Kinetic and potential energy increase. The limb is then  propelled  into  swing  phase  after  toe  off  (swing phase generation — Fig. 2cc3). At swing phase rever-sal (Fig. 2cc4), the next period of absorption begins.These  issues  will  be  discussed  further  in  a  subsequent section  on  the  interaction  of  potential  and  kinetic  energy.While  stance  will  be  plotted  before  swing  for  the purposes  of  this  article,  not  all  authors  agree  with  this convention. Many publications depict swing phase first.In  fact,  DeVita  [29]  felt  strongly  that  toe  off  should mark  the  beginning  of  the  gait  cycle  and  that  swing phase  be  depicted  before  stance.  His  reasoning  was based  on  the  observation  that  both  net  joint  torquesFig.  3.  Variation  in  gait  cycle  parameters  with  speed  of  movement.For each condition, the bar graph begins at initial contact on the left and represents two complete gait cycles or strides. Note that as speed increases,  time  spent  in  swing  (clear)  increases,  stance  time  (shaded)decreases,  double  float  increases,  and  cycle  time  shortens.  Informa-tion for this graph comes from data collected at the Motion AnalysisLab at Gillette Children’s Specialty Healthcare. *Data for elite sprint-ing  is  from  Vaughan  [16]. -- Allison Felsenthal Founder RUNWITHALLI LLC

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