An important part of multidirectional speed development is the enhancement of technique of speed and agility related actions involved in match play (e.g., sprinting, curvilinear sprinting, side-step cutting, pivoting, etc.). To develop technique, it is essential for practitioners to know what ideal technique is of these actions. This blog revisits a traditional first principles approach (Lees, 1999, 2008, 2018) based on a recent article by us that outlines how to create and use a technical framework to assist with technical coaching to enhance multidirectional speed.
The Need for a Technical Framework for Coaching Agility Actions
An essential part of speed, change of direction speed and subsequently agility development is to evaluate an athlete’s technique performing the range of sports specific actions associated with expressions of agility in the athlete’s sport. Technique analysis involves a 5-stage process: 1) preparation, 2) observation, 3) fault diagnosis, 4) intervention and 5) re-evaluation (Lees, 2008; 2018). Perhaps the most important stage is the preparation, which effectively involves developing a ‘knowledge structure’ of what should be observed (e.g., an ideal technique model) and then decide how the evaluation can be conducted, allowing the analyst to focus on ‘critical features’ of the performance during the fault diagnosis phase and develop a subsequent appropriate intervention. Thus, applied practitioners (e.g., S&C coaches, physiotherapists, coaches, etc.) are required to understand what optimal technique may be for a given action and how to develop the athlete towards this optimum technique. What compounds this further for practitioners involved in developing agility with athletes, is the plethora of actions potentially involved and how they interact during match play (e.g., side-step cutting, cross-cutting, pivoting, linear and curvilinear sprinting, side-shuffling, backpedalling, etc.) that require a biomechanical/ technical understanding to coach. Some of these actions such as sprint running including both acceleration and maximum velocity phases have been heavily researched and understood to inform the coaching of linear sprint activities. However, many of the instantaneous and locomotion actions involved with expressions of agility are not so well understood or lack research to fully understand the important aspects of technique for performance and / or injury risk mitigation. That said, there is a large expectancy for applied practitioners from non-biomechanics backgrounds to be fully versed in understanding and integrating the biomechanics literature on changing direction to various angles for example and be able to translate this into coaching their athletes from the community to elite level.
“Technique analysis involves a 5-stage process: 1) preparation, 2) observation, 3) fault diagnosis, 4) intervention and 5) re-evaluation”
The majority of biomechanical research into change of direction (COD) has tended to focus on the postural or technique factors that are associated with knee joint loads (McLean et al., 2005; Dempsey et al., 2007; Sigward & Powers, 2007; Celebrini et al., 2012; Jamison et al., 2012; Kristianslund et al., 2014, Sigward et al., 2015; Jones et al., 2015; Jones et al., 2016) during the plant step of such actions due to the reported association to non-contact anterior cruciate ligament injury incidences (Olsen et al., 2004; Faude et al., 2005; Brophy et al., 2015; Walden et al., 2015; Montgomery et al., 2018; Johnstone et al., 2018). Given the logistical issues of incorporating 3D motion analysis to screen athletes for hazardous COD mechanics, evaluation tools have been developed to help practitioners evaluate athletes in this regard in the field (Jones et al., 2017; Dos’Santos et al., 2019a, Dos’Santos et al., 2021; Weir et al., 2019; Della Villa et al., 2020). The Cutting Movement Assessment Score (FIGURE 1), we developed in recent years (Jones et al., 2017; Dos’Santos et al., 2019a, Dos’Santos et al., 2021) could provide a ‘knowledge structure’ for practitioners to identify technical faults with athletes to provide avenue for intervention regarding injury risk mitigation. For further information on the CMAS, please check out our recent blog. However, the CMAS is limited to side-step cutting actions ranging from 30 to 90° and focuses on technique / movement evaluation in relation to injury risk potential and does not offer an adaptable approach more focused on performance. For example, whilst errors that could result in elevated knee joint loads can be identified, practitioners also need to understand how this may impact performance. Indeed, performance improvements maybe the primary goal of athletes and coaches. Furthermore, remember athletes regardless of their sport will perform a variety of instantaneous and locomotion actions, and thus, practitioners require an approach to develop a knowledge structure that caters for the variety of performed actions and considers execution of technique from both performance and injury risk perspectives.
FIGURE 1 | The Cutting Movement Assessment Score. Key: PFC = Penultimate foot contact; FFC = final foot contact.
A Framework Approach to Technique Analysis
As a sports biomechanist, an approach I often adopt to establish a ‘knowledge structure’ of a sports action or event that requires technique assessment is to develop a technical framework (Lees, 1999; Lees, 2008; Lees, 2018). This traditional first principles approach has been the focus of a recent article by us (Jones et al., 2021, linked above), that aimed to bring this approach to the attention of practitioners involved with the speed and agility development of athletes.
A framework approach (Lees, 1999; Lees 2008; Lees, 2018) involves breaking down a skill into phases and sub-phases (often key instances within a phase), describing the body position and movements, stating the aim to each phase/sub-phase before then applying biomechanical principles or principles of movement (FIGURE 2) and then perhaps expanding the model to identify factors that influence the implementation of the movement principles or identifying common technique errors. An essential part of the process is the application of movement principles (TABLE 1). A movement principle is a description of how a movement should be performed based on biomechanical /mechanical principles (e.g., impulse-momentum relationship) (Lees, 2008). Applying movement principles separates general movements that have no influence on performance (e.g., whether your fingers should be extended or flexed during sprinting) with those that impact performance (e.g., tightly flexed knee and dorsi-flexed ankle during the swing phase when sprinting to reduce moment of inertia and increase limb speed). A step-by-step process of how to develop a technique framework is provided below using an example for a 180° pivot.
FIGURE 2 | applying biomechanical principles or principles of movement.
TABLE 1 | Key Movement principles relevant to change of direction actions.
For a complete list of movement principles see Lees (1999, 2008, 2018) and Jones et al. (2021).
Breakdown Into Phases and Sub-Phases
Most sports actions / events can be split into 4 phases: 1) initiation, 2) preparation, 3) execution and 4) follow through. In applying this to a 180° pivot, the action can be divided into initiation (approach), preparation (adjustment of steps prior to final foot contact), execution (plant step) and follow-through (re-acceleration) (FIGURE 3). Of course, the actions involved during initiation and follow-through may differ e.g., sprinting to side-shuffling on approach or re-acceleration phases. Thus, there is flexibility to the process to help the practitioner adapt for the different ways in which common actions interact during expressions of agility during match play.
FIGURE 3 | A breakdown of a 180° pivot into phases (Red font) and sub-phases (Yellow font).
Developing Technical Frameworks for Each Multi-Directional Speed Action
For cyclical locomotion actions such as sprinting it would be more logical to divide into stance (ground contact) and flight phases and subsequently sub-phases / key instances within these phases (e.g., touchdown, mid-stance, take-off, early flight, mid-flight and late flight). Of course, here, this should be adapted for different phases of sprinting (e.g., acceleration (early, mid, late) and maximum velocity phases). Once the action has been broken down into phases and sub-phases, a description of key postures, joint positions and / or movements is required (see Technical Framework for a 180 Pivot°, free to download below).
In this regard, a similar approach is adopted by ALTIS with their Kinogram Method, and readers are directed to an introductory article available here: The ALTIS Kinogram Method (simplifaster.com) or download a free e-book from their official site: Free Resources • ALTIS. Nevertheless, the multi-directional nature of team sport match play and training necessitates an understanding of each specific action (see an earlier blog) to develop effective performance and injury risk mitigation training methods. For those working in team sports, it is recommended that practitioners holistically establish their athletes’ multi-directional speed capabilities to develop the appropriate knowledge structures of each action for technical coaching. Merely focusing on refining the technical development of one particular aspect (typically acceleration) may be short selling your athletes by neglecting the other key aspects that they frequently perform in their sport.
Applying Movement Principles
The next step is to add an aim to each phase from a biomechanical or sports specific perspective and consider which movement principles from TABLE 1 apply in each phase of the skill/action. Please note that Table 1 is not an exhaustive list, but we have highlighted the key principles in context of changing direction and sprinting. FIGURE 4 highlights the aims and illustrates several movement principles that apply in each phase of the 180° pivot. The aim of the approach phase is to achieve the highest controllable velocity whilst visual scanning. The velocity attained during this phase is dependent on the interaction between step length (SL) step frequency (SF) (whole body running speed). SL is dependent on force production generated during ground contact (force production) and maybe mediated by the co-ordination principles stretch-shorten cycle and simultaneous joint movements, whereas SF may depend on the speed of the leg recovery action (limb speed). The contra-lateral limb-movement (action-reaction principle) is also important to preserve angular momentum about the longitudinal axis of the body. The preparation phase requires a reduction in velocity and to optimally position the body for the plant step (speed-accuracy trade-off), thus, the penultimate (and possibly antepenultimate foot contact and steps prior) is required to generate a braking action (force production) through placement of the foot in front of the centre of mass, marked flexion at the knee and hip to lower the centre of mass, and thus, apply a braking force for longer (range of motion) and subsequently increase braking impulse. The aim of the execution phase is to perform the directional change safely and efficiently. Thus, the foot is placed in front of the body (change of direction) to facilitate braking and propulsion into the opposite direction. A firm base is requred to push from (force production) and the lowering of the centre of mass at this stage with a period of double support (balance) enhances the athletes stability at this point allowing a safer execution phase (i.e., lower risk of ankle and knee injury). The propulsion (maximum knee flexion to take-off) sub-phase of the execution phase maybe faciltated by use of the stretch-shorten cycle and simultaneous joint movements as the athlete triple extends the 3 lower limb joints into the first re-acceleration step. Controlling the athletes dynamic stability (balance principle) during the first few steps is important to take advantage of angular momentum generated through the centre of mass being ahead of the foot during ground contact. To maximise velocity during the re-acceleration phase the interaction of SL and SF (whole-body running speed) will determine the athletes velocity and once again the force produced during each footfall during re-acceleration could be enhanced with greater extension range of motion at the 3 lower limb joints (range of motion principle) and simultaneous joint movements faciliated by a vigorous arm drive (action-reaction principle).
FIGURE 4 | The aims (Green font) and application of movement principles (white font) during the various phases of a 180° pivot.
Identifying Factors that Influence Performance
Once the movement principles have been applied, the next step it to recognise factors that may influence technical execution, which may largely be physical factors (access below). Some external factors may impact technical execution such as sports rules (i.e., in basketball & netball), carrying or progressing with a sports implement and shoe-surface interface and impact of weather (e.g., application of the force production movement principle). In terms of internal factors in a 180° pivot, the approach phase may be influenced by fast reactive strength through use of the stretch-shorten cycle with each foot contact and linear sprint speed in this case, whilst the preparation and execution phases may be dependent on eccentric strength of the knee extensors and flexors (Jones et al., 2009; Jones et al., 2017; Jones et al., 2019). The ground contact time of the plant step during 180° turns/ pivots can be ≥ 400 ms (Sasaki et al., 2011; Spiteri et al., 2015; Jones et al., 2016b, Dos’Santos et al., 2017; Jones et al., 2017), suggesting slow reactive strength muscle strength qualities are important here (Dos’Santos et al., 2018) alongside concentric strength of the lower limb joints as the athlete (FIGURE 4) extends the lower limb joints during the propulsion sub-phase of the execution phase. Similarly, concentric lower limb strength and linear sprint ability will be physical factors important for technical execution of the re-acceleration phase. During the execution phase, controlling the largest segment of the body (the trunk) suggest isometric trunk strength may be essential for controlling dynamic stability during this phase as well as alleviating high knee joints loads of the plant leg (Zazulak et al., 2007 a/b).
ACCESS FREE TECHNICAL FRAMEWORK FOR A 180° PIVOT HERE
Application of the Framework
The development of the framework and application of movement principles has implications for the ‘critical features’ that should be the focus for qualitative technique evaluation and subsequent intervention. For instance, observing the running action of the approach should focus on the contralateral limb movement (action-reaction principle), leg recovery action (tightly flexed knee and dorsi-flexed ankle during swing up until a high knee lift position, before sweeping motion from the hip with the foot landing almost under the centre of mass) (limb speed), short ground contacts through limited knee and ankle flexion (the foot strike should be towards the forefoot in a neutral ankle position) during ground contact (stretch-shorten cycle), and simultaneous triple extension of lower limb joints at take-off. The preparation phase should observe the foot placement in front of the centre of mass, whilst leaning back (range of motion principle) to facilitate braking along with marked flexion of the lower limb joints to lower the centre of mass to prolong braking (range of motion principle) and arrive at the final foot plant in an optimal position (balance principle). During the execution phase, observing whether the athlete plants one leg out in front of the body (change of direction principle) to facilitate the direction change, with the athlete’s centre of mass low and a period of double support (balance principle). Noticing whether the athlete’s knee flexes to eccentrically load the knee extensors (stretch-shorten cycle) before extending with the ankle and knee towards (simultaneous joint movements/ range of motion principles) take-off of the execution phase and whether the upper limbs are held close the body (whole-body rotation principle) to allow faster rotation out of the turn. As the athlete re-accelerates, observations should focus on the first 2 ground contacts which should be behind the centre of mass to control the athlete’s angular momentum (balance principle), with shorter more frequent steps (whole body running speed) initially to maximise net horizontal impulse (drive index). Also observing whether the athlete extends the lower limb joints to help generate horizontal force with each ground contact (simultaneous joint movements/ range of motion principles), whilst using a vigorous arm drive (action-reaction principle).
“A framework approach involves breaking down a skill into phases and sub-phases, describing the body position and movements, stating the aim to each phase/sub-phase before then applying biomechanical principles or principles of movement”
Having identified faults with an athlete against the model created, the drills utilised as part of the intervention, need to be grounded in the underpinning movement principle(s). For example, if an athlete does not sufficiently brake prior to the plant step leading to a double hop on the final ‘plant’ step. To improve this deficit, deceleration drills (start-stop over 5 metres finishing in a split stance) (FIGURE 5) should be used whereby emphasis is on placing the leg in front of the centre of mass whilst leaning back during penultimate foot contact (range of motion principle) and lowering the centre of mass through flexion of the hip and knee (range of motion and balance principles) as they then transition into the final split stance position. Once mastered, intensity can be increased by increasing the length of the drill and the associated greater velocity of approach and observing whether these technical aspects are upheld.
FIGURE 5 | start-stop over 5 metres finishing in a split stance.
The development of technique within such a drill can be affected by the magnitude and quality of the instruction and feedback from the coach. Coaches should use cueing techniques to direct athlete’s attention to 1 or 2 aspects of technique during a demonstration or during feedback (Winkelman, 2018). Cues should be externally focused (where the focus of attention is on the environment), as this has been shown to improve timed COD performance (Porter et al., 2010; McNicholas & Comyns, 2020), although, this may be influenced by training experience (Winkelman et al., 2017). Nevertheless, once the critical features have been identified, cues can be developed as part of the framework to focus the athlete’s attention during coaching sessions (see FIGURE 6). Effectively, extending the framework to encompass possible coaching cues for some of these critical features may assist the practitioner in identifying the important biomechanical characteristics of the action and how these could be effectively communicated to the athlete.
Summary
An essential part of developing multidirectional speed with athletes is to evaluate athlete’s technique in performing actions associated with expressions of agility in their sport. This requires a technical / biomechanical understanding of these actions that are often under-researched and interact in an often-complex manner during match play. For practitioners responsible for multidirectional speed development with athletes, who have a limited biomechanical background, it may be difficult to understand what ideal technique may be in such actions before then seeking ways to enhance the execution of such actions. This blog revisits a traditional first principles approach to creating and using a technical framework to help practitioners develop a biomechanical and technical understanding of sports actions that maybe pertinent to expressions of agility in the sport they work in to assist with their coaching. For more information see: Lees et al, 2008, 2018 and Jones et al., 2021.
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