"Effortless rowers do not waste a movement. Any movement should be well sequenced and have only a positive impact on the performance of the hull" Chris O'Brien, as cited in Notle, 2011
Building a basic technical model.
Basic rowing technique explained (Exeter Rowing Club, 2008).
If we are to understand how rowing technique can be optimised to increase shell velocity to achieve maximum propulsion while minimising resistance, we must first understand the stroke phases essential to the execution of correct technique.
Rowing is a periodic movement that incorporates the following stroke phases: catch, drive, finish (sometimes refereed to as the release), and the recovery. Optimal rowing requires the repetition of thee phases as precisely as possible for more than 200 strokes during competition. Therefore, 'competent rowing requires good stroke to stroke consistency' (Smith & Loschner 2002).
Correct rowing technique has implications not only on overall boat velocity but will also impact injury prevention and recovery. Injury prevention and management are often overlooked but should be considered factors in the development of correct technique.
Rowing is a periodic movement that incorporates the following stroke phases: catch, drive, finish (sometimes refereed to as the release), and the recovery. Optimal rowing requires the repetition of thee phases as precisely as possible for more than 200 strokes during competition. Therefore, 'competent rowing requires good stroke to stroke consistency' (Smith & Loschner 2002).
Correct rowing technique has implications not only on overall boat velocity but will also impact injury prevention and recovery. Injury prevention and management are often overlooked but should be considered factors in the development of correct technique.
Catch
Catch Position
|
Drive
Early Drive
Late Drive
|
Release
Release Position
|
Recovery
Early Recovery
Mid Recovery
Late Recovery
|
Rumball et al. 2005; Fenner, B. 2006
Photos: Exeter Rowing Club, 2008
Photos: Exeter Rowing Club, 2008
Rowing force summation
In rowing, energy is transferred from one component to the next. This transfer takes place from the rower to the oar and then to the boat (Kleshnev, 2011 in Nolte). The diagram below shows the force summation achieved by a rower executing optimal, efficient technique. It is known that the legs contribute roughly half (46.4%) of total rowing power; the trunk is responsible for approximately one-third (30.9%), while the arms and shoulders combined are responsible for the remaining 22.7% (Kleshnev, 2000). Efficient rowing technique is critical due to its relationship with force summation that results in coordination and utilisation of body segments in order of largest to smallest. Correct application of the legs, legs and trunk, trunk and arms and finally arms and shoulders has considerable implications on the efficiency and effectiveness of a rower (Notle, 2011).
Force summation of a rower. (source: sportsmedbiotech, 2009)
Why is this important?
There are three distinct forces that act on the rower: forces exerted at the foot, the seat and the hand. Force is generated directly at the foot stretcher and the rower acts as the mechanical link between the force exerted at the foot stretcher and the force transferred via the hands into the oar. The force transitioned into the oar via the hands is dependent on the force exerted on the foot stretcher and the acceleration of the body (Baudouin & Hawkins, 2002).
A rower's goal is to propel their boat as quickly as possible over 2000m. This requires intimate knowledge of the force production behind the movement they are repeating approximately 200 times during competition. When cumulative forces are applied (rower force summation) at a distance from the centre of rotation of an object (in this case, the oar lock) an overall force is created and transferred in to the oar, increased boat velocity results. If the distance over which force is applied increases (moment arm) the magnitude of force applied will also increase (Blazevich, 2010). Note: a careful balance must be struck between the moment arm and the force capable of being generated by the rower.
A rower's goal is to propel their boat as quickly as possible over 2000m. This requires intimate knowledge of the force production behind the movement they are repeating approximately 200 times during competition. When cumulative forces are applied (rower force summation) at a distance from the centre of rotation of an object (in this case, the oar lock) an overall force is created and transferred in to the oar, increased boat velocity results. If the distance over which force is applied increases (moment arm) the magnitude of force applied will also increase (Blazevich, 2010). Note: a careful balance must be struck between the moment arm and the force capable of being generated by the rower.
- A rower can increase or decrease their moment arm (refered to in rowing as altering the gearing) by altering the 'button' (circled in the diagram below). The oars button sets the leverage of the oar and therefore has ultimate affect on any change in the moment arm. If the outboard is increased dramatically then the load felt at the blade end of the oar will also increase dramatically. What results is a difficulty in accelerating the handle of the oar from the catch position to the finish position (see picture below). A particularly tall or strong rower or crew may benefit from increasing the moment arm while a smaller, less strong rower or crew may struggle with the increased load experienced by a significant gearing change.
- Sequential sequencing of the lower limbs, trunk and arms may lead to a more effective rowing stroke, and therefore greater average boat velocity (Lamb, 1989; Kleshnev & Kleshnev, 1998; Nelson et al., 1983; Hume & Soper, 2001, as cited in Hume & Soper, 2004).
Diagram of an oar highlighting the potential change in outboard and inboard source: basics of rowing physics.
Rowing faster: The ultimate aim!
Biomechanical principles (bottom row) based on overarching principles (middle row) with the main aim of rowing faster (Notle, 2011).
Rowing is a complex sport. There are a number of factors that affect the ability to row fast, some of which are related to the boat and its relevant structures, others relate to the rower. A rower's technical ability to optimise the application of power generated from the phased movements of the catch, drive, release and recovery is the focus of this blog.
The components of fast rowing that can be manipulated by the rower and which will form the basis of this blog include:
The components of fast rowing that can be manipulated by the rower and which will form the basis of this blog include:
- Fluctuations in boat velocity
- Blade Efficiency
- Stroke length
- Force curve
- Horizontal movement
Rowing faster; Blade force counteracts drag forces
Blade force has been found to be the sole propulsive force to counter the drag forces (water, air and hydrodynamic factors). The oar acts as the link between the force generated by the rower and the blade force via a transition of force to the boat via the oarlock. The force exerted on the oar handle is a result of the phased muscular activation of the rower (see rowing force summation above). Oar handle force and movement are affected by joint strength and torque-velocity characteristics of the rower (Baudouin & Hawkins, 2002).
Force is generated during the complete range of motion of the oar through the water (Baudouin & Hawkins, 2002). It is therefore the job of the rower to maximise the propulsive impulse. Particularly given that all other forces are acting to slow the boat's overall momentum.
Maximising propulsive impulse can be achieved via technically correct phased movement patterns and summation of forces generated by the rower. If a rower understands where propulsive impulse is most effective (mid drive) or when the blade is perpendicular to the boat, then they are able to work to improve efficiency of application at this point of the stroke cycle.
Force is generated during the complete range of motion of the oar through the water (Baudouin & Hawkins, 2002). It is therefore the job of the rower to maximise the propulsive impulse. Particularly given that all other forces are acting to slow the boat's overall momentum.
Maximising propulsive impulse can be achieved via technically correct phased movement patterns and summation of forces generated by the rower. If a rower understands where propulsive impulse is most effective (mid drive) or when the blade is perpendicular to the boat, then they are able to work to improve efficiency of application at this point of the stroke cycle.
Why is this important?
As is stated above, blade force is the only force capable of being applied by the rower to counter the considerable drag impulses acting against the forward movement of the rowing boat. Therefore, a rower must maximise the propulsive impulse exerted by the blade against all other negative drag factors e.g. water resistance, air resistance, the mass of the rower traveling towards the stern of the boat during recovery and the impulse of the rower applying force against the footstretcher in the opposite direction of the boats momentum.
Fluctuations in boat velocity
Fluctuations in boat velocity are unavoidable due to the biomechanical requirements of rowing; a propulsive drive phase and a recovery phase that results in a deceleration of boat velocity. Therefore, increases and decreases in boat velocity can be attributed to the periodic movements associated with rowing. Also, fluctuations in boat velocity can be attributed to the change in a rower's centre of gravity, relative to the boat. During the drive sequence a rower's mass is transferred towards the bow along a horizontal plane. Inversely, during the recovery, a rower's mass transitions from the bow to the stern along the same horizontal plane.
Increased fluctuations in boat velocity has been identified as a major factor in the identification of optimal rowing performance and are generally associated with less successful technique (Nolte, 1991; Del Monte & Komor, 1989, Cited in Soper & Hume, 2004). What does the following force-velocity time curve tell us?
Increased fluctuations in boat velocity has been identified as a major factor in the identification of optimal rowing performance and are generally associated with less successful technique (Nolte, 1991; Del Monte & Komor, 1989, Cited in Soper & Hume, 2004). What does the following force-velocity time curve tell us?
A typical force-velocity time curve of a rower.
|
Not only a fantastic video but a great example of fluctuations in boat velocity.
Slutbucketism, 26th April 2011 |
Why is this important?
It is known that a large proportion of the drive sequence is in fact non propulsive due to the orientation of the blade through the water, secondly, the acceleration of the rower's mass towards the bow of the boat against the foot plate causes the boat to decelerate towards the stern. The only force to counteract this movement is that of the oar in the water. Therefore, a rower must be able to maximise the power exerted by the oar in the propulsive phase, when the oar is perpendicular to the boat.
In addition, a rower is able to minimise the deceleration experienced by the boat at the catch position by optimising technical proficiency. If a rower is able to exit the release position in a sequential motion and allow the boat to in effect 'run' underneath them while placing their blades in the water before the drive sequence begins, then they will limit the fluctuations in boat velocity that are unavoidable within the sport of rowing (Notle, 2005).
In addition, a rower is able to minimise the deceleration experienced by the boat at the catch position by optimising technical proficiency. If a rower is able to exit the release position in a sequential motion and allow the boat to in effect 'run' underneath them while placing their blades in the water before the drive sequence begins, then they will limit the fluctuations in boat velocity that are unavoidable within the sport of rowing (Notle, 2005).
the importance of Stroke Length
Considerable length! (source: carlosdinares.com)
Stroke length can be determined by the total arc of the blade as it moves trough the water from catch position to finish position. Stroke length shows a direct correlation with stroke rate (SR), the amount of strokes taken per minute. What is unclear however, is the relationship between stroke length and on water performance (Soper & Hume, 2004). It is known that length of stroke begins to decrease as SR increases. This could be due to the rower's inability to maintain technical efficiency at a higher SR. It has been highlighted that force application is most inefficient at the catch and finish positions, therefore a reduction in overall stroke length might be considered appropriate in the presence of insufficient force application (Sanderson & Martindale, 1986 as cited in Hume and Soper, 2004).
Why is this important?
Stroke length allows the rower to optimise propulsive impulse. As stated above, stroke length and SR show a direct correlation. A linear increase in boat velocity has been seen as SR increased from 20 to 32 strokes/min, the challenge for any rower or crew is in determining optimal stroke length without negatively affecting fluctuations in boat velocity (Notle, 2011).
As suggested, technical efficiency decreases as SR increases. This occurs for a number of reasons; physiological demands increase at a higher SR, transfer of mass from bow to stern happen faster and technically demanding aspects of the rowing stroke occur more frequently with less time for consideration of the rower. What results is a decrease in efficency due to increased fluctuations in boat speed. More time is spent hindering boat propulsion rather than accelerating the boat in a positive direction.
In particular, less experienced rowers and their coaches must take into consideration the following when deciding on appropriate length of stroke:
As suggested, technical efficiency decreases as SR increases. This occurs for a number of reasons; physiological demands increase at a higher SR, transfer of mass from bow to stern happen faster and technically demanding aspects of the rowing stroke occur more frequently with less time for consideration of the rower. What results is a decrease in efficency due to increased fluctuations in boat speed. More time is spent hindering boat propulsion rather than accelerating the boat in a positive direction.
In particular, less experienced rowers and their coaches must take into consideration the following when deciding on appropriate length of stroke:
- Stroke rate (SR)
- Physiological demands of the rower.
- Technical proficiency at varied length and SR.
A brief Note on injury prevention and management
Rowers are prone to numerous and potentially serious injuries, often due to overuse associated with the extreme forces generated by and transmitted via the body. Injury prevention is best achieved via correct technique, discussed at the beginning of this blog. In addition, adequate stretching and warm up, correct body swing and force summation along with post-rowing spinal stretching and correction will go some way to preventing injuries associated with over use (Fenner, 2006; Rumball, 2005.
Factors associated with rowing specific injuries include:
Factors associated with rowing specific injuries include:
- Poor technique.
- Lack of fitness.
- Over Training.
Take home message
Rowing performance can be improved by two basic mechanisms:
- Increasing the propulsive impulse.
- Reductions in drag impulses applied to the system during the stroke cycle.
- Blade force dynamics.
- Fluctuations in boat velocity and why they occur.
- Force Curves (when the boat is at its fastest and when it is slowest) and understand why this occurs.
- The importance of length of stroke.
How Can we use this information?
If a rower is attempting to propel their boat faster in order to be more competitive over a distance of 2000m, they must explore the notion of fluctuations in boat velocity and why they occur. Technical improvement can be achieved via technical feedback of the phased movements of the stroke cycle (catch, drive, release and recovery). Along with an understanding of correct, strong anatomical body position to support the transfer of power produced by the force summation of the sequence form catch to finish. In addition, rowers are able to increase or decrease their moment arm to achieve optimal blade dynamics. Optimal blade dynamics is achieved when the blade is perpendicular to the boat and as such the rower should aim to accelerate the handle with greater force from this point, right through to the finish. Essentially, handle speed increases from catch to finish, as does the 'snap' of the legs, in particular from mid drive sequence through to the finish. If optimal efficient sequencing occurs then an optimal efficient force curve will be achieved.
Once an efficient drive sequence has been achieved, then the rower must begin to focus on the recovery. During the recovery phase, a rower must allow the boat to 'run' beneath them. An efficient transfer of mass from bow to stern must occur, once again in a technically correct manner (see building a basic technical model at the beginning for clarification). By limiting the transfer of mass from bow to stern the rower is, in effect, limiting the overall fluctuations in boat velocity and optimal positive horizontal movement can be achieved. Finally, length of stroke must be considered as we know that technical efficiency decreases as length of stoke decreases and SR increases. Any fluctuactuation in length of stroke should be initiated ti improve propulsive impulse.
Now that we have reviewed some of the biomechanical principles necessary to optimise boat velocity and overall boat speed, we can begin to explore some essential drills required for technical improvement. A coach should first identify aspects of a rower's performance that are technically deficient and hinder propulsive boat movement. Only then is a coach able to identify the necessary drills required to begin fixing the problem. Below are a series of basic drills that allow the rower to improve their technique, with the goal of optimising efficient technique for faster rowing.
A great deal of information has been covered in what is a very technically demanding sport. If rowers focus on doing the basics extremely well the the are on the right track to achieve technically proficient and fast performances.
Once an efficient drive sequence has been achieved, then the rower must begin to focus on the recovery. During the recovery phase, a rower must allow the boat to 'run' beneath them. An efficient transfer of mass from bow to stern must occur, once again in a technically correct manner (see building a basic technical model at the beginning for clarification). By limiting the transfer of mass from bow to stern the rower is, in effect, limiting the overall fluctuations in boat velocity and optimal positive horizontal movement can be achieved. Finally, length of stroke must be considered as we know that technical efficiency decreases as length of stoke decreases and SR increases. Any fluctuactuation in length of stroke should be initiated ti improve propulsive impulse.
Now that we have reviewed some of the biomechanical principles necessary to optimise boat velocity and overall boat speed, we can begin to explore some essential drills required for technical improvement. A coach should first identify aspects of a rower's performance that are technically deficient and hinder propulsive boat movement. Only then is a coach able to identify the necessary drills required to begin fixing the problem. Below are a series of basic drills that allow the rower to improve their technique, with the goal of optimising efficient technique for faster rowing.
- Catch placement drill - A stationary drill focusing on the motion of the catch, recovery slide speeds, and catch timing. While sitting six inches from the catch with the blades either squared or feathered, rowers work on moving towards the catch in time with the person in front of them, placing the blade with the correct amount of backsplach/foresplash. No rowing takes place. The distance from the catch can be increased until the rower begins the drill from the finish.
- Catch sequence drill - A moving drill also focusing on set at the catch, the motions of the catch, recovery slide speeds and catch timing. This five part drill begins with the rower rowing only the first six inches of the slide, increasing to legs only, legs + back, legs + arms and then regular rowing. Novices should do this drill on the feather with at least one pair setting up the boat. More experienced rowers can do this drill at full crew.
- Exaggerated layback - The body lays back further at the finish than usual to work on body swing and acceleration.
- Exaggerated slowness - The strokerate is lowered to 14 or lower on the paddle and 16 and below on full pressure. Exaggerated slowness works on works on timing and gives the coxswain or coach extra time to spot exactly where problems occur on the recovery as well as identifying individuals who rush on the recovery.
- Freefall drill - Alternate rowing one stroke at 1/4 slide, then one at at full slide. This drill highlights any tendencies to rush in the boat.
- Pause drill - Pausing every on to five strokes at the finish, hands away, forward body angle, 1/4 slide, 1/2 slide, 3/4 slide positions. Pause drills work on set, timing and slide control.
- Pick drill - This drill begins at reduced slide rowing at quick pick - arms only, swing pick- arms and body angle, followed by rowing at 1/4, 1/2, 3/4 and full slide. This basic drill is one of the most common. The pick drill is used in warm-ups as well as individual parts of the stroke.
A great deal of information has been covered in what is a very technically demanding sport. If rowers focus on doing the basics extremely well the the are on the right track to achieve technically proficient and fast performances.
How else can we use this information?
Information explored throughout this blog has a practical application for any sport where periodic movement patterns occur. Such sports include swimming, kayaking and wheelchair sports. Any sport that experiences acceleration due to a sequenced movement pattern followed by a deceleration in the recovery phase should explore the concept of velocity fluctuations and why it occurs. By understanding the competing forces at play, coaches and athletes are better able to limit or even counteract such potential forces in the pursuit of a more efficient and effective technical model. In affect, athletes are able to generate more 'bang for their buck'!
Resources for Biomechanic Analysis and technical improvement:
Video: 26mins
Includes tips on better rowing technique, fault correction and exercises and drills Price: $48 Available from: http://www.rowingaustralia.com.au/products.cfm?id=23 |
Textbook: A comprehensive guide for achieving excellence in the sport of rowing. It provides you with techniques for mastering different phases of the stroke; training strategies for increasing strength and efficiency for maximizing speed; and, tapering plans for peak performance at the highest levels of competition.
Price: $25.07 (includes free postage) Available from: http://www.bookdepository.com/book/9780736090407?redirected=true&gclid=CKfJzZXhybYCFQxepQodHxIAlw |
App: A very useful App for iPhone and iPad that allows the capturing of video footage of athlete performance. Footage can be analysed quickly with the addition of biomechanical markers and voice analysis layered over the top for, two videos can also be compared side by side. Coaches Eye allows for instant technical feedback and for comparisions to be made between skilled and less skilled rowers.
Price: $5.47 Avaliable from: App store |
References:
Text sources:
Baudouin, A., & Hawkins, D. (2002). A biomechanical review of factors affecting rowing performance. British Journal of Sports Medicine, 36, 396-402.
Blazevich, A. (2010). Sports biomechanics, the basics: optimising human performance. London: A&C Black.
Fenner, B. (2000). Level 3 Rowing Technique & Biomechanics. Rowing Australia Inc. Belconnen, ACT
Kleshnev, V. (2000) Power in rowing. In Y. Hong (Ed.) Proceddings of XVIII International Symposium on Biomechanics in Sports, Perth, 224-228.
Notle, V. (2011). Rowing Faster. Human Kinetics, Champaign, IL
Notle, V. (2005). Rowing Faster. Human Kinetics, Champaign, IL
Rumball, J., Leburn, C., Di Ciacca, S. & Orland, K. (2005). Rowing Injuries. Sports Medicine, 35(6), 537-555
Soper, C., & Hume, P. ( 2004). Towards an Ideal Rowing Technique for Performance: The Contributions from Biomechanics. Sports Medicine, 34(12), 825-848
Smith, R., Loschner, C. (2002). Biomechanic feedback for rowing. Journal of sports sciences, 20(10), 783-91
Photos & Videos:
Exeter Rowing Club, (2008). About rowing. Retrieved from http://www.exeterrowingclub.com/general/rowing.php
Slutbucketism, (2011, 26th April). M2- Mens Coxless Pairs Athens Olympics 2004 (video file). Retrieved from http://www.youtube.com/watch?v=OKUZrJH98mQ
sportsmedbiotech, (2009). Retrieved from http://sportsmedbiotech.blogspot.com.au/2009/11/rowing-injuries-possible-effects-of.html
Baudouin, A., & Hawkins, D. (2002). A biomechanical review of factors affecting rowing performance. British Journal of Sports Medicine, 36, 396-402.
Blazevich, A. (2010). Sports biomechanics, the basics: optimising human performance. London: A&C Black.
Fenner, B. (2000). Level 3 Rowing Technique & Biomechanics. Rowing Australia Inc. Belconnen, ACT
Kleshnev, V. (2000) Power in rowing. In Y. Hong (Ed.) Proceddings of XVIII International Symposium on Biomechanics in Sports, Perth, 224-228.
Notle, V. (2011). Rowing Faster. Human Kinetics, Champaign, IL
Notle, V. (2005). Rowing Faster. Human Kinetics, Champaign, IL
Rumball, J., Leburn, C., Di Ciacca, S. & Orland, K. (2005). Rowing Injuries. Sports Medicine, 35(6), 537-555
Soper, C., & Hume, P. ( 2004). Towards an Ideal Rowing Technique for Performance: The Contributions from Biomechanics. Sports Medicine, 34(12), 825-848
Smith, R., Loschner, C. (2002). Biomechanic feedback for rowing. Journal of sports sciences, 20(10), 783-91
Photos & Videos:
Exeter Rowing Club, (2008). About rowing. Retrieved from http://www.exeterrowingclub.com/general/rowing.php
Slutbucketism, (2011, 26th April). M2- Mens Coxless Pairs Athens Olympics 2004 (video file). Retrieved from http://www.youtube.com/watch?v=OKUZrJH98mQ
sportsmedbiotech, (2009). Retrieved from http://sportsmedbiotech.blogspot.com.au/2009/11/rowing-injuries-possible-effects-of.html
