A new approach to lateral speed for rugby
Dean Benton is a Level II Sprints Coach with postgraduate qualifications in sport science and currently works with the Queensland Academy of Sport as a strength and conditioning specialist. He is a young and enthusiastic sprint coach who has found some success in integrating sport science to develop his coaching skills with positive performance outcomes. During his time as a track and field coach at the Australian Institute of Sport, Dean utilised sport science resources to enhance athlete performance. In this paper Dean demonstrates how he has used quantitative data to identify problems and monitor progress of his young athlete.
BIOGRAPHICAL DATA
Athlete: Craig Sconce
DOB: 20/06/81
Event: 100/200m
Coaching period: January 2002 to April 2003 (14 months)
PBs pre-coaching intervention: 100m – 10:76s; 200m 21.75s
PBs post-coaching intervention: 100m – 10:58s; 200m 21.23s
Australian ranking pre-coaching intervention: 100m – 23rd; 200m – 43rd
Australian ranking post-coaching intervention: 100m – 10th; 200m – 5th
General comments
The comments I have made in relation to the particular athlete’s technical model were based on qualitative and quantitative data. Qualitative data, including two lower limb kinematic reports (LLKR) dated 24/09/02 and 11/01/03, were supplied by the Biomechanics Department of the Australian Institute of Sport (AIS). . Additionally, the photo sequence shown above that was captured by the AIS Biomechanics Department provides a visual reference of the athlete’s maximum velocity running mechanics. Although the LLKR was not generated from the photo sequence shown, I feel the footage provides a fair representation of the athlete’s maximum velocity running mechanics during that time period.
Touch down position:
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Strengths: |
§ Generally the nature/quality of his foot strike was always quite good, but there was still some room for improvement;
§ Slight upper lean with trunk; § Balanced arm action. |
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Weaknesses: |
1. Slightly ‘piked’ at the hip upon toe down (hip height too low);
2. Foot contact slightly too far in front of the Centre of Gravity (C of G); 3. Slightly too much thigh separation angle at toe down & slightly behind from a temporal standpoint. |
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Priorities to improve and why (based on the above): |
1. Improve hip height by reducing trunk flexion at contact to ensure greater summation of lower limb torque into greater ground force production (GFP);
2. Decrease horizontal distance of foot contact relative to C of G to reduce braking forces in order to reduce Ground Contact Time (GCT) and, in turn, reduce stride time to increase stride frequency 3. Reduce thigh separation angle at toe down to ensure the swing leg is in a good position to assist in GFP of recovery leg. Improving opposite leg approach velocity will assist this process as well. |
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Interventions both direct & indirect (based on the above): |
1. (a) Encouraged athlete to run taller at speed [direct]; (b) Improving leg muscle stiffness with plyometric training [indirect]; (c) Strengthening of the smaller hip muscles (postural) via Mach running drills [indirect].
2. (a) Encourage athlete to lean forward from the toes rather than from the hip and keep contact underneath body [direct]; (b) Improvements made in left hip extension & left quadricep ROM as ‘flagged’ by physiotherapy reports. This was done in an effort to improve symmetry between hips which, in turn, provides the athlete with the means (time) to correct right leg overstriding [indirect]; 3. (a) Encouraged athlete to recover the swing leg ankle and ‘pick it up’ faster at speed [direct]; (b) Improving the athlete’s ability to use the stretch shortening cycle (SSC) of the hip flexors with elastic tube resistance work [indirect]. |
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Objective measures of improvement from pre test to post test (based on weaknesses): |
1. a.) Hip heights (m) at contact pre test: Right 0.89, Left 0.94; b.) Hip heights (m) at contact post test: Right 0.95, Left 0.95.
2. a.) Horizontal distance (m) from toe to hip at contact pre test: Right 0.56, Left 0.49; b.) Horizontal distance (m) from toe to hip at contact post test: Right 0.45, Left 0.46. 3. a.) Thigh separation at contact (deg) pre test: Right 0.35°, Left 0.11°; b.) Thigh separation at contact (deg) post test: Right 0.11°, Left 0.13°. |
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Any conclusions and suggestions: |
1. Improvements in hip height at contact and symmetry of hip height with both legs at contact;
2. Improvements in the reduction of horizontal distance of foot contacts relative to C of G and symmetry of distance between legs; 3. Decreased asymmetry in thigh separation. |
Mid support phase:
| Strengths: | § General postural integrity & pelvic control (in frontal plane) is quite good. |
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Weaknesses: |
1. ‘Collapse’ at hip & knee during mid support (amortization), particularly the right leg;
2. Tendency to ‘hunch’ & tighten shoulders during mid support; 3. Roundness of thoracic spine during mid support. |
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Priorities to improve and why (based on the above): |
1. Make hip & knee heights/angles more symmetrical during mid support to ensure better economy/rhythm at speed. Reduce collapsing at hip and knee in order to reduce GCT and, in turn, reduce stride time to increase stride frequency.
2. Tight/tense shoulders can only inhibit arm action which, in turn, affect the ability of the arms to counteract the torque produced by the hips; 3. The spine as a system will always tolerate stress/strain more effectively when it is aligned. |
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Interventions both direct & indirect (based on the above): |
1. (a) All plyometric training (irrespective of the training phase) was unilateral in nature; progressive overload of plyometric training was varied by regulating amplitude & number of contacts [indirect]; (b) Maximum strength training of the prime movers was predominantly unilateral in nature [indirect]. (c) Glute medius/minimus muscles were targeted for strengthening via hip abduction/rotational work to ensure pelvic control during mid support [indirect];
2. Athlete was encouraged to relax shoulders during smooth-fast technique runs (~90%). Also, as a coaching cue, the athlete was encouraged to visualize maximizing distance between shoulders and ears [direct]; 3. A very stiff thoracic spine was noted in physiotherapy reports. Hence, functional development exercises were added to the athlete’s program to stretch, strengthen & mobilize the thoracic region. Massage also complimented this intervention [indirect]. |
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Objective measures of improvement from pre test to post test (based on weaknesses): |
1. (a) Hip heights (m) at amortization pre test: Right 0.89, Left 0.93;
(b) Hip heights (m) at amortization post test: Right 0.93, Left 0.95; (c) Knee angles (deg) at amortization pre test: Right 151°, Left 161°; (d) Knee angles (deg) at amortization post test: Right 152°, Left 163°. |
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Any conclusions and suggestions: |
1. Some improvements in hip height were made in preventing the athlete from collapsing from a relative & absolute standpoint during mid support (amortization) phase. However, asymmetries still remain between right and left knee joints with minimal change reported. |
Toe off position:
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Strengths: |
§ Proficiency in achieving ‘powerline’ (line from heel to hip) with back leg at toe off – ensures effective summation of forces throughout the ’drive’ or ‘propulsive’ phase;
§ Ability to achieve/maintain a neutral pelvic position & to achieve reasonable vertical displacement with hips; § Good knee drive was complimented with good rear-side & front-side arm mechanics. |
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Weaknesses: |
1. Front lower leg (shank) in powerline position slightly too open & not in parallel alignment with rear leg angle;
2. Tendency to ‘hunch’ & tighten shoulders; 3. Insufficient dorsi-flexion of front foot (recovery leg). |
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Priorities to improve and why (based on the above): |
1. Need to achieve front leg shank to line up parallel with rear leg angle at toe off (true powerline) for two reasons: (a) to ensure swing leg stays compact to maximize vertical ‘lift’ and, in turn, GFP during the rear support phase of the support leg; (b) to ensure knee joint angles do not open too early in the commencement of the ground preparation phase, which reduces angular velocity of forward swing of the thigh;
2. Encourage athlete to reduce shoulder tension, so arm drive maximizes ‘lift’ ® propulsion ® GFP. |
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Interventions both direct & indirect (based on the above): |
1. (a) Speed bounding & contrasted speed bounding with fast- relax sprinting – athlete was encouraged to hold/load front shank with special emphasis on leg approach speed [direct];
(b) Resisted Mach ‘B’ running drills with sled in which the athlete was encouraged to hold a preferred leg position [indirect]; (c) Resisted leg exercises, such as elastic tubing attached to the ankle during hip extension work, in which the athlete was required to ‘catch’ the shank in the powerline position when the elastic recoiled; this lends itself to the development of specific hamstring eccentric strength [indirect]. |
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Objective measures of improvement from pre test to post test (based on weaknesses): |
1. Objective measures in regard to front leg shank angle & rear leg angle at toe off were not collected. However, thigh separation at take off position increased with some improved symmetry:
Thigh separation (deg) at take off pre test: Right -96°, Left – 105°; Thigh separation (deg) at take off post test: Right -105°, Left – 100°; |
| Any conclusions and suggestions: |
None. |
Mid flight phase:
| Strengths: | 1. Balanced rear-side & front-side arm mechanics; good separation of elbow from torso with front-side arm mechanics;
2. Good thigh separation in mid flight phase. |
|
Weaknesses: |
1. Ground preparation for both legs generally inactive and having a ‘dropping-floating’ action toward ground, rather than an active ‘grab’ back into the track;
2. Angle of knees of both legs during ground preparation were extended too early from a temporal standpoint in mid-ground preparation phase; 3. Slight asymmetry of right foot to left foot in respect to horizontal foot velocity prior to contact. |
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Priorities to improve and why (based on the above): |
1. Velocity of legs just prior to ground contact needed improvement to maximize the acceleration of the athlete’s C of G with each respective stride;
2. To maintain a slightly more ‘compact’ or ‘folded’ leg during the early phase of ground preparation (viz. knee angles), which lends itself to greater angular velocity of the thigh during mid- late ground preparation. 3. Improve symmetry of horizontal foot velocity prior to contact to minimize braking forces on right foot & maximize positive GRFs. |
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Interventions both direct & indirect (based on the above): |
1. (a) Initially, due to fact the athlete had a limited training history in bounding & plyometrics per se, we commenced bounding & speed bounding in sand; this enabled the athlete to focus on hip extension/leg approach velocity without the concerns of impact forces [direct]; (b) After time, progression was made to performing speed bounds on a Mondo track in racing flats [direct]; (c) Resisted Mach ‘B’ running drills with sled whereby athlete was encouraged to ‘snap’ leg back whilst holding the sprint posture [indirect]; (d) Special strength hip extension exercises were employed with cables with an ankle attachment as part functional development, preceding athletic development (strength training) in a gym setting [indirect].
2. See intervention #1 in ‘toe off section’. 3. Resisted Mach ‘B’ running drills with sled whereby athlete was encouraged to ‘snap’ leg back whilst holding the sprint posture [indirect] |
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Objective measures of improvement from pre test to post test (based on weaknesses): |
1. (a) Horizontal foot velocity (m/sec) relative to hip pre test: Right
–6.0, Left –8.0; (b) Horizontal foot velocity (m/sec) relative to hip per test #2: Right –7.7, Left –8.2; 4. Right foot movement across ground prior to contact reduced from 4.3 to 1.9 m/s such that it is now similar to the left foot contact (1.5m/s), which lends itself to reducing unbalanced braking during initial stance phase. |
| Any conclusions and suggestions: | 1. Velocity of foot during ground preparation and prior to ground contact increased & became more symmetrical as a result of
interventions. |
Summary:
The coaching interventions (14 months) aimed at improving the maximum velocity mechanics of this athlete was reflected in the improved results of the athlete’s maximum velocity (10.87 m/s to 11.11 m/s). The resultant changes were manifested in changes in stride frequency. Stride frequency improved from 4.55 s/s to 4.65 s/s (conditions pending). Stride length remained consistent around 2.39m (conditions pending). A maximum velocity of 11.11 m/s suggests that the athlete’s performances over both 100m & 200m can still be improved appreciably. Initial and late acceleration mechanics are still an area for improvement in the athlete’s technical development that requires some attention.
I feel it important to point out that it is very difficult to infer as to exactly which single intervention (i.e., training modality) was responsible for the positive improvements & symmetry in the athlete’s kinematic parameters. I can only deduce it was a combination of the different modalities I have outlined, which served to improve the athlete from either an athletic, functional & technical standpoint or, all of the above.
The positive changes that took place with the athlete were as a result of a team approach to problem solving. I was fortunate to have access to kinematic data from the AIS Biomechanics Department on a regular basis. However, it was the interpretation of the data and the subsequent implications for possible improvements in the athlete’s technical model that made the difference. I acknowledge the support of my former colleague and mentor Esa Peltola (AIS), for his past and on going personal and professional assistance in regards to the preparation of high performance sprinters.
References:
Rosemond, D. (2003). AIS Biomechanics Dept – Lower Limb Kinematic Reports. Canberra: Australian Institute of Sport.
Rosemond, D. (2003). AIS Biomechanics Dept – Competition Analysis Reports. Canberra: Australian Institute of Sport.
Benton, D., & Mallett, C. (2002). The utility of the Mach drills. Modern Athlete and Coach, 40(1), 9-13.
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