Sprint Biomechanics PBL Msc

Overview:

The main objectivies of sprinting are to have a quick reaction time, a rapid intial accerleration, a smoothe continue pick up with a long maintenance phase at maximum velocity whilst ensuring minimum decerlation.

The critical featers of sprinting is full extension through the driving leg, raising the knee horizontally, having a vertical or slight leaning forward trunk, running on balls of feet, short ground contact times and running with relaxed shoulder girdle.

Background

The Sprinter, has a problem with the early accerlaration phase in races in her 100 m and 200m she is being left behind in the first 10m. The problem is more apparent in her 100 and from the video footage I was privvy she accerlates much better in the 200m. The athlete in her Q&A stated the reason for this difference in performance is she likes to chase someone.

 

She has returned from hamstring injuries. It was stated her shinsplints (medial tibial compartment syndrome) had been successfully treated with orthotics, for last 4 years.   This is inaccurate as during the testing sessions she pulled up in agony due to the pain of the shinsplints. Her times have not improved in 4 years.

 

Athletes personal bests is 11.63 sec for 100m and 23.3 sec for 200m, in 2009. Running at her best she was 1.1 second and 1.3 seconds outside the worlds best 4 years ago. She has failed to make any progress in the interim four years. Our athlete has good reaction times of of 0.14-0.19 which is in line with elite category sprinters. According to the International Association Of Athletics Federation standards an false start is anything under 0.100 sec.

 

In 2012 an masters class cohort of students evaluated her sprint start and made changes and recommendatation accordinly. Our aim is to build on the their findings and help her progress in her sprint acceleration phase aswell.

 

Athletehas enagaged in an gym program over the last couple of years and has got much stronger in the gym yet this has failed to translated to performance on the track, especially during the acceleration phase of the 100m. She is being left 1 or 2m short in the first 10m and comes back well in the last 40m. Her 200m race does not appear to have the same problem.

 

 

Picture 1: Rear-view Track Testing Session Tues 18/06/13

 

Testing Procdure

 

Equipment

Optojump * 2, Timing Gates * 3, High Speed Camera and Video Camera

On Outdoor track. FMS testing kit.

 

Screening

The Screening Video files where corrupt and unable to view them on my computer.   The Straight Leg Raise was circa 70-75 degrees on both legs and the fibula in the superior fibula tibula joint was congested, indicative of external rotated in both joints of leg, to greater degree on right.   The in line lunge showed bilateral hip instability with medial knee movement.

A slight anterior pelvic tilt with increase lumbar lordosis and increased kyphosis in sideview standing. Supine her neck was tight on palpation specifically major C3/4 right facet joint and minor Left facet joing C4/5 dysfunction.   Picture 1   and picture 7 show an imbalance between right and left shoulder distrubution this would most likely result findings in the cervical spine in my opinion.

Future protocol should have a pre written check list to record data manually, with a tester and an assistant, and use two cameras to record to ensure usable files. The use of a Goniometer would be helpful plus marking up anatomical reference points on the subject.

The 3 timing gates where set up at 0m, 20 m and 40 m’s, the optojump where set up with 5 pairs of bars at 0m and and 20 meters.  Athleteran 3 complete sprint to 40m. Unfortunately we only received incomplete results from 20m optojump and no results from the 0 m optojump. The athlete was also in some considerable discomfort due to her medial tibal compartment syndrome.

Further problems existed in that our athlete decelerated near 35m just prior to last timing gate at 50 m, this may be partly due to camera position ahead of her, suggestion would be to have a finish line at 50m to encourage her to run at maximum acceleration. The timing gates being so close together may have impeded the athlete from maximum arm swing suggestion would be to have to wider apart.

Suggestions

Athletewas asked to set up your block start position as normal. Her hip height was measure for centre of gravity height. This was shown to have improved from last years 85cm to 75 cm which is still not optimal. According to Coh et al (1998) their female athletes where set up at 32% their standing height. Centre of gravity (COG) calculated at 32% of Athleteheight at 156cm would be 50 cm which is considerably lower than her current set up at 75 cm. With increased flexibility and correction of imbalances it would be advisable and worthwhile. Coh et al (20066) recommends testing the block face angle also and this would be recommended in future investigations.

 

Picture 2: Side View angle 116              Picture 3: Side view 126 angle rear leg 2012

Their have been improvements in her block set up her left leg is 38cm nad her right back 65 cm from the start line given her an improved toe to toe spacing 27cm in last years testing 2012, it was seen to be 32 cm. This is withing Coh et al (1998) range of 25cm-30 cm for bunch/bullet sprint start. The bunch start may result in considerably slower 10yard and 50 yeard times (Hay 1952 citied in Harrison and Commyns 2005). The medium front and rear toe values are 40-55cm and elogated are 60cm-70cm (Coh et al 1998).

 

Using a crouched start is more effective that a standing start as it alters the athletes position enabling them to move their centre of gravity rapidly ahead of feet, the athlete has to accelerate or fall. (Adrian & Cooper, 1995). Accordingly the medium start block has the optmum ratio of step length and frequench as a result contact phase and flight times in the first ten steps which are key performance features in the intial phase of sprinting. (Coh et al 2006)

 

The main purpose of the crouch start is to leave the blocks at the highest velocity possible. The position taking in the blocks has a bearing on the velocity. The bunch start limits the impluse placed on the blocks as the athlete is only in contact for a short time. The elongated start results in more force as a results of increased contact times between the athlete and blocks yet restricts the force exerted in the set pase. The medium start is the optimum posistion for maximum velocity as it allows the athlete to create the most force. (Harrison and Commyns 2005).

 

In the off peak season it would be my suggestion to further reduce Athletecentre of gravity by a further 10cm and then gradually move towards her more optimal suggestd height in the reagion of 50cm eventually.  As clearly seen in picture 7 AthleteCOG is higher than taller sprinter in the 2013 season at start of 100m.

 

In accordance with Coh et al (1998) recommend angle of the rear leg in the set position of 115 degrees Athletemeasures 116 degrees which is a 10 degreee improvement on 2012 finding.

 

From view the video analsysi of Athleterunning the 100m it is seen that she needs to extend more through her support leg and flex her knee more, drive her knee up and out for longer whilst driving more through extended knee. According to Novacheck (1998) in each step there is “period of absorptions followed by a period of power generation and the power generated provides energy for forward propulsion, the magnitude of which is directly related to the athletes speed).

 

It is evident in her start of the 100m her eys and head looks down at track a few inches in front of feet and her opponents tend to have the head up and with their eyes further down the track. For every 1 degree the head is out of line with the spine it becomes roughly nine times heavier for the muscles of the neck to hold. The average head weaight between 4.6 kg and 5.4kg, taking Athletehead as weight 4.6kg this becomes 41.4 kg of weight the neck muscle have balance. And that just 1 degree out it apparent from the picture 8 than it is in the region of 20-30 degree off.

 

As her coach, you are happy with her gym work and progress yet this is failing to transfer to on track performance gains. It is my suggestion to ustilise imagery of the sprinting whilst doing gym work to enable carry over of strength gain carry over in accordance with Gaul et al 1990 findings. They found that imagery can facilitatethe transfer of physiological training to performance.   This supports the findings of Paivio (1985 who categorises the use of imagery into two general functions motivationa and cognitive. Paivio (1985) stated the motivation function of imagery lies in the ability to represent behaviours associated with a goal/situation.   He stated the cognitiive effects was accredited to the practice of skills and strategies. Gaul et al (1990) found that imagery can group who utilised imagery of sprinting in conjunction with the peak power cycle training improved their sprint times.

 

Using weight vests (Cronin and Hansen 2006) with loads of 15 and 20% of body mass increased sprint times to 10m (7.5% and 10%) respecively and increased sprint times to 20 m by (9.3% and 11.7%). Cronin et al 2008 alsow showed sprint performance improvement is sled and weight vest. Resistend sprinting using a resisted treadmill erogmeter (Vick California, 90278) showed improved acceleration in american footballers over 9 m. Other studies have shown sled towing increases acceleration over 5m

 

Isokinetic Dynameter testing of the hamstrings and quads throughout the year to access the ratio is in line with recommended levels. The ideal ratio as quoted by Peter Francis 2013 for males is 66% and females is 75%.

 

Improvement have occurren in start and early accleration phases since testing in 2012. The sprinters rear leg has change from a 126 degrees to a more optimal 116 degrees circa Coh et al recommended 115 degrees. Her hip height in the set position has droped from a very high 85 degrees to an improved 75 degrees.

She has got faster to 20m from an average of 3.42 sec to 20m in 2012 to an average of to 3.15 to 20 meters in 2013 testing session. Unforutnately the data for 20m-40 m was incomplete due to a technical error and having only 1 complete set of results means nothing to compare to previous years. The basic rule of thumb for scienficitic expeirment protocol is 3 repeatable results.

The Angles used in these pictures, throughout report, are not entirely accurate as the positioning of the camera affects the reading of the angles. With the absence of ananotmical markers for accurate reference these given values are a guide.

 

Picture 5: Kyphotic posture start posiition Picture 6: Normal Flexible Spine in Start Pos.

 

Picture 6 7:   2013 100m guest start                     Picture 7 8: Cervical spine misalignment eyes down.

 

Pic 8 9 &0: 2013 100m guest accerlation phase Knee angle at circa 133-151 versus faster runners at 113 knee ankle

 

Pic: 10 2013 200m guest start Triple extension through hip, knee and feet

 

 

Once the shinsplints conditions have been resolved then it would be highly beneficial for our sprinter to do more plyometric drill, starting with low intensity drills, moving to low to medium, then when strong enough progress to high and very high intensities accordingly. Examples of low intessity plyometrics are tuck jumps, split jumps and squat jumps,. Low to mediums examples are standing long jump, standing hop, standing jump for height. High and very high intensity plyometrics are hops and jump into sand pit with an eleven stride approach, bounds with 7 stride run up, jumps down and up, bounding uphill and bound hop bound hop for 30m.

Shinsplints is a common name for medial tibial stress syndrome. During the early stand phase of gate foot pronation allows the foot to accomadate the irregular underfoot conditions and eases ground reaction forces. The action of pronation involves muptiple joint movements at the rearfoot and the midfoot. It is thought that too much foot pronation, overpronation, causes extra stresses on musculosketal structures of the lower limb and results in injuries such as medial tibial stress syndrome or paterllafemoral pain.

Conventional medical management of this type of pain has involved the use of non-steroidal anti-inflmmatories (NSAIDs), orthotics, taping and physiotherapy. Therapetic taping has been found to the most effective (Cheung and Chung 2011) and othotics have been shown to show a reduction in stress. Overall the effect of orthosis is unclear.

Cheung and Chung 2011 undertook as methodical review of the effects of foot orthoses on lower extremity kinematics during running. Their findings suggest that further research is requited looking at design parameters and biomechanical variables to enhance the effectiveness of clinical use of orthotics.  Dr Ferber (2007) found in his review on the influence of foot orthoses on lower extremity running mechanic found that foot orthoses are effective for the treatment of overuse injuries yet studies reviewing lower extremity kinematics and kinetics had reported conflicting results. Some studies where carried out on healthy subjects whilst other on injured subjects.

In regards to our athlete, it was stated in our briefing that she had orthotics made four years ago and that they had the shinsplints under control. It was made clear at the track session that this is an incorrect assertion as she clearly still suffers from shinsplints. Orttotics need to be reviewed every six months in order to assess their effectivness and to see if the perscription needs to be changed.

The overpronation appears to be still present as is the medial tibial compartment pain. Feet balancing and arch rebuilding exercises are advised under suitable medical supervision.

Our sprinter would strongly be advised to see medical help with regards this condition, specifically to attend an physiotherapist where not invasive methods such as ultrasound, PNF stretching, Rhytmic Technique, Myofascial Release may be applied (she reports being sore for a week after soft tissue work). Self care daily routine is strongly advised included self massage using elbow on the medial tibial compartment, daily foam rolling of whole body including shins. Behm et all 2013 found that foam rolling helps increase range of movement without decreasing muscle activation or force.

The following suggestions are also useful to impliment, aqua jogging to allow the shinsplints recover whilst gaining the chephalic pump benefits of water submersion.

Some simple exercises to help her shinsplints include walking on heels with feet turned out, walk on heels with toes turned in, walk on tip toes with heels turned out , walk on tip toes with feet turned out, walking on inside of feet and outside of feet. Stretching the calf and hamstring muscles priot to exercise and calf raises. (Mens Fitness 2002 Article)

The next time we meet with our athlete it would be beneficial to look at her arches which are quite likely to be falling and accordingly perscribe her very simple arch buidling exercises to reinstate the natural arch in her feet.

As previously stated the screening tests where not usable and no written recorded results to verify them. From the testing it was seen that Athletehad restricted range of motion in the straight leg raise tests between 75-80%. A slight anterior pelvic tilt with increase lumbar lordosis and increased kyphosis. Her neck was tight on palpation specifically C3/4 right facet joint and Left C4/5. Again attendance with a physiothearpist to normalise these dysfunctions would be advised.

Anterior pelvic tilt lengthens the hamstrings and shortens the quads correcting this imbalance would improve power of quad to hamstring ratio. A further study using a dynameter would be proposed to A access current quad to hams ration and b in the future test the rehab treated and correction of pelvic tilt has normalized quad:hams ratio strength.

 

Not having physio and foam rolling regularly is like an F1 driver refusing to bring his car to a mechanic pre and post race in my opinino. Other form of physio such as PNF, METs, theraband work , balance work, rthymic thenique as are virtually pain free.

 

Pilates is useful to help increase core strength, aid flexibility promote mind body control in my opinion. Phrompaet et al 2011 found that pilates can be used as an modality to stabilise lumbo pelvic stability by improving flexibility, enhacing control mobility of trunk and pelvic segments. They also asertained it may prevent the predispoistion to axial musculoskeletal injury.

A further pilates study by da Fonseca et al 2011 found that gait analysis changed following 15 sessions of pilates, increased walking speed and decreased pain was also seen in the low back pain suffers piltates group. Increasing weight discharge between left and right leg would be benefical to a sprinter.

As Athletecoach you believe her diet is sufficent, however as an international level athlete it is vital that she engages the service of a professional sports nutritionist to montior and access her dietary requirements to optimise her performance and training adaptations (Tipton et al 2006).  They highlighted the importance of maintaining digestive function and avoid discomfort or race day. Tipton et all 2007 also highlight that creatine may be effective in increaseing muscle mass and strength and may increase repeat sprint peformance during training. Food Diary and activity levels need to double checked and perhaps some ammendments make to help fuel our athlete to run faster, training better and recovery in an optimum time.

Psychology of the athlete is vital, a willingness to engage in the training methods, utilize visualization to reinforce and correct biomechanics and race strategy. Goal setting needs be specific (PB in x time), measurable (Time and distance), achievable, (can be done in time allotted), realistic (a coach potato does not become sub 10sec 100 m sprinter in a year) and time (date and time for achievement of goal. Visualisation of correct technique copying over the 200m sprint start to the 100 m sprint start incorporation correct technique and optimum performance. Kosslyn (1994) describes the imagery process generating the image prior to transforming and maintaining it, it is hypothesizes that the imagery capabilities of the subject captures their proficiency in carrying out processes. (Williams and Cummin 2011).

Previous imagery research show that imagery practice can enhance Motor Imagery (Cumming and Ste-maire,2001; Rodgers et all, 1991). Subsequent practice from session improved subject ability to visualize and feel their intervention. Suggested imagery to be utilized by our athlete would be to imagine the finish line is at 105 m instead of 100m to avoid deceleration at 100m and to imagine chasing an imaginatory athlete, whilst leading the field herself for the 100m.

Finally yet importantly ample recovery is viatl for the body to recharnge and recover, allowing treaining adaptaions and aid lactate buffering (Denadal et al 2004). Including active recovery and passive recovery into her daily routine.

 

2013 Timing Gate results

0-20m 20-40m 0-40m
Trial 1 3.13 2.25 5.38
Trial 2 n/a 2.21 n/a (First Timing gate failed)
Trial 3 3.12 2.22 5.34
Trial 4 3.19 n/a n/a
Hip Height 75cm
Left (Front) Right (Back)
Block Setting 38cm 65cm

 

 

 

2013 Optojump results

TFlight TContact Height Pace Step Speed
171
0.113 0.1 1.6 4.69 183 8.59
0.094

 

2012 results

Timing Gates Blocks Distance
Trial 1 5meters 10meters 20meters Front block from start line 56cm
1.4 2.13 3.4 back block from start line 88cm
0.73 1.27 Distance between each block 32cm
Trial 2 1.42 2.17 3.43
0.75 1.26 Height of hip from ground at start 85cm
Trial 3 1.4 2.15 3.41
0.75 1.26
Trial 4 1.43 2.18 3.44
0.75 1.26
Trial 5 1.42 2.15 3.42
0.73 1.27

 

References

External devices (including

orthotics) to control excessive

foot pronation

▶ Cheung RT, Chung RC, Ng GY. Effi cacies of different external controls for excessive

foot pronation: a meta-analysis. Br J Sports Med 2011;45:743–51.

Shinsplints Are a Pain in the Tibialis.

Source:

Men’s Fitness Aug2002, Vol. 18 Issue 8, p74 2p.

Abstract:

Focuses on shinsplints or medial tibial stress syndrome in runners. Causes; Treatment; Workout designed for preventing shinsplints.

ISSN:

15412776

Document Information:

Publication Type: Journal Article Update Code: 20020718

Accession Number:

6987776

Database:

SPORTDiscus with Full Text

Section:

HEALTH UPDATE THE PREHAB WORKOUT

SHINSPLINTS ARE A PaIN IN THE TIBIALIS

Review article

The influence of custom foot orthoses on lower extremity

running mechanics

1,2*Dr Reed Ferber, PhD, ATC, CAT(C)

1 Faculties of Kinesiology and Nursing, University of Calgary, Calgary, Alberta, Canada

2 Running Injury Clinic, University of Calgary, Calgary, Alberta, Canada

 

Journal of Sport & Exercise Psychology, 2013, 35, 60-71

© 2013 Human Kinetics, Inc.

Sarah E. Williams, Sam J. Cooley, and Jennifer Cumming are

with the School of Sport and Exercise Sciences, University of

Birmingham, Edgbaston, Birmingham, UK.

Layered Stimulus Response Training Improves Motor

Imagery Ability and Movement Execution

Sarah E. Williams, Sam J. Cooley, and Jennifer Cumming

University of Birmingham Cumming, J., & Williams, S.E. (2012). Imagery: The role of

imagery in performance. In S. Murphy (Ed.), Handbook

of Sport and Performance Psychology (pp. 213–232). N

Williams, S.E., & Cumming, J. (2011). Measuring athlete

imagery ability: The Sport Imagery Ability Questionnaire.

Journal of Sport & Exercise Psychology, 33, 416–440.

PubMed

Cumming, J., & Ste-Marie, D.M. (2001). The cognitive and

motivational effects of imagery training: A matter of perspective.

The Sport Psychologist, 15, 276–287.

Rodgers, W., Hall, C., & Buckolz, E. (1991). The effect of an

imagery training program on imagery ability, imagery use,

and figure skating performance. Journal of Applied Sport

Psychology, 3, 109–125. doi:10.1080/10413209108406438

 

JOURNAL OF SPORT & EXERCISE PSYCHOLOGY, 1990.12, 366-375

Imagery as a Method of Enhancing Transfer

From Training to Performance

Geraldine H. Van Gyn, Howard A. Wenger,

and Catherine A. Gaul

University of Victoria

 

Feltz, D.L., & Landers, D.M. (1983). The effects of mental practice on motor skill

learning and performance: A meta-analysis. Journal of Sport Psychology, 5,25-57.

Paivio, A. (1985). Cognitive and motivational functions of imagery in human performance.

Canadian Journal of Applied Sport Sciences, 10, 225-285.

Nutrition for the sprinter

KEVIN D. TIPTON1, ASKER E. JEUKENDRUP1, & PETER HESPEL2

1School of Sport and Exercise Sciences, University of Birmingham, Birmingham, UK and 2Research Centre for Exercise and

 

Health, Faculty of Kinesiology and Rehabilitation Sciences, KU Leuven, Leuven, Belgium

(Accepted 2 August 2007)

 

Hawley, J. A., Tipton, K. D., & Millard-Stafford, M. L. (2006).

Promoting training adaptations through nutritional interventions.

Journal of Sports Sciences, 24, 1 – 13.

References:

 

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Brown, L. Ferrigno, V and Santana, J (2000) Training for Speed Agility and Quickness Human Kinetics, Champaign Illinois

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Vick, K Improving running speed and acceleration with a resisted sprint ergometer, Applied Performance Research NO DATE GIVEN

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Resisted Sprint Ergometer

KEN VICK

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International SportMed Journal, Vol.8 No.3, 2007,

pp.97-106, http://www.ismj.com

Official Journal

Review article

The influence of custom foot orthoses on lower extremity

running mechanics

1,2*Dr Reed Ferber, PhD, ATC, CAT(C)

1 Faculties of Kinesiology and Nursing, University of Calgary, Calgary, Alberta, Canada

2 Running Injury Clinic, University of Calgary, Calgary, Alberta, Canada

 

Effects of Pilâtes Training on Lumbo-Pelvic Stability and Flexibility

Sureeporn Phrompaet, MSc; Aatit Paungmali*, MPhty, PhD; Ubon PIrunsan, MPhty, PhD;

Patraporn Sitilertpisan, MSc, PhD

Asian Journal of Sports Medicine, Volume 2 (Number I), March 2011, Pages: 16-22

 

Sports Biomechanics

May 2008; 7(2): 160–172

Effects of weighted vests and sled towing on sprint

kinematics

JOHN CRONIN1,2, KEIR HANSEN1,2, NAOKI KAWAMORI1, &

PETER MCNAIR3

 

 

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