Movement analysis is a key concept in any manner of sport that involves mobility, in terms of movement skills and motor control. This study brings together different methods or measurements, to further understand its perception as well as the limits that could potentially restrict progress in the advancement of research into movement analysis. The objective of this study, would also be to understand how it is best to integrate these techniques into applied settings or everyday situations.
Analysing movement skills is a growing trend worldwide, especially amongst those pursuing sporting endeavours. More and more sports are being exposed to the importance of sports science and as a result, the study of motor control systems and techniques by coaches remain crucial in improving the sporting performance of athletes.
Learning more about these different tools and techniques available would not only further a coach’s expertise in the field of human movement, but one would then be able to know what is necessary in a bid to utilise properly, the correct methods to aid athletes in pushing beyond their current boundaries.
For instance, with the aid of 3D motion capture, ideally the “gold standard” in the measurement of spatiotemporal parameters, joint kinematics and force during gait, one can analyse the movement patterns in the motion of a sprinter in the drive phase of a sprint as the athlete comes exploding out of the blocks.
This measurement analysis tool can not only allow the sprinter and his coach to playback and view the movement executed, but they would in turn also be able to rectify what could have been done better are what is potentially lacking in the athlete’s training load and, thereby, work towards steps on improvement in training regime.
Lately, non-invasive or minimal invasive motion capture approaches, like vision-based motion capture systems and angular measurement sensors have surfaced. These methods can be utilised for in-field kinematics data collection, minimally interfering with on-going work. However, there are definitely two sides of the coin for kinematic measurement due to adopted sensors and algorithms, an in-depth comprehension for each approach would aid in the decision in adaptation for usage. (Seo et al. 2017).
Outline of Techniques & Tools
Knowing the different planes of motion – Sagittal, transverse and frontal, is crucial in laying the foundation for understanding human movement skills. In each of these planes, several movements around the joint occur, mainly the lateral, longitudinal and vertical axes.
Firstly, the sagittal line is determined by separating the body into right and left halves with an imaginary line. Forward and backward movement, parallel to that line happens here.
Similarly, the frontal plane is exhibited by splitting the body into front and back halves. Lateral movement, parallel to the line happens here.
Lastly, the transverse plane is shown by dividing the body into the upper and lower trunk. All movement parallel to the waistline, classified as rotational movement, occurs here.
Next, understanding fundamental movement skills (FMS), which are basic movement patterns involving various body parts, affording the foundation for physical literacy, is another crucial tool necessary. FMS provides the foundational movements, or precursor patterns, to the more specialised and complex skills used in play, games and specific sports. It describes the ability to instruct the human body to execute an action accurately and with confidence. It also identifies the physical, social, cognitive and emotional attributes required to do so effectively, as expressed by Broomfield’s study on human kinetics in the Complete Guide to Primary Gymnastics (2011).
Movement screening methods are then used to assess an individual’s movement pattern. By understanding FMS and its various movement patterns involved, one would hence be able to segment movement individually to determine the specific skill being expressed. With this knowledge in mind, the selective functional movement assessment (SFMA), a movement based diagnostic system, can then be utilised in identifying causes of pain by considering the breakdown of movement patterns and locating maladaptive movement structurally and repeatedly.
Gait analysis is a method that generates a greater understanding on human movement. Beyond evaluation of the manner of movement via the naked eye, it goes even more in depth, where several factors are put together to form a complete representation the gait of an individual. Mainly ranging from habitual traits, to proprioception to individual levels of mobility, stability, flexibility, and functional strength. Manners in which gait is measured range from 2D video analysis to 3D motion capture. Specific gait parameters however, require specific tools, all of which are readily available
In addition, objective measurement tools are also employed in movement analysis. Mainly, these consist of 3D motion capture, force plates and surface electromyography (SEMG). Furthermore, the development of technology has enabled new devices to be introduced in analysing human movement, often hailed to be more cost-effective, practical and convenient as opposed to traditional tools.
Summary of Literature
To begin summing up the different human movement assessment techniques, it shall start from a bottom-up approach, whereby foundation will be first discussed before the rest of the structure is examined.
The foundation of physical literacy, FMS shall be first observed as the foremost apparatus necessary for fundamental movement patterns. By examining the phases as to how movement evolves over time, especially in children, as they acquire motor skills.
Gallahue (1993) proposes that children move through a developmental progression in the acquisition of motor skills. Translating to the reflexive movement phase, rudimentary movement phase, fundamental movement phase and the specialized movement phase. Generally, progression of motor skill acquisition goes according to this sequence, though the rate of procurement varies from child to child.
The reflexive movement phase ranges from birth to about 1 year of age. Here, the infant engages mainly in reflex movement.
In the rudimentary movement phase, this consists of basic motor skills acquired in infancy: reaching, grasping and releasing of objects. Also, sitting, standing, and walking. Skills in this phase attained during the first couple of years, form the basis for the fundamental phase.
The fundamental movement phase occurs from ages ranging across 2 to 3 and ages 6 and 7. During this phase, children gain increased control over their gross and fine-motor movements. This process involves the development and refinement of skills such as running, jumping, throwing, and catching. Control over each skill progresses through initial and elementary stages before arriving at a mature stage. Children in this phase first learn skills in isolation before combining them with other skills such as coordinated movement.
The specialized movement phase begins at about 7 years of age and continues through the teenage years and into adulthood.
Gallahue cautions that maturity and physical activity alone do not ensure that children will acquire fundamental movement skills in the preschool years. Children who do not master these skills are frustrated and experience failure later in recreational and sports activities. Knowledge of the process of fundamental motor skills can aid in designing suitable curriculum and activities to enable children to ultimately do so.
Moving on, functional movement screen is a tool designed to identify injury risk through compensatory movement patterns and inefficient mobility that potentially reduces performance. The SFMA is a series of 7 full-body movement tests designed to assess fundamental patterns of movement such as bending and squatting in those with known musculoskeletal pain.
As mentioned, gait analysis can be as modest as observation to note irregularities made visible by the naked eye. Systematic gait analysis however, incorporates a top-down and bottom-up visual orientation, ideal upon identifying subtle deviations. A top-down orientation delivers statistics on symmetry, quantity, and quality of arm swing; pelvic rotation; pelvic tilt; and lateral trunk shift. Bottom-up orientation analyses ankle, subtalar, midfoot, and hallux motion symmetry, quantity and quality. Focus of these different approaches pinpoints potential exaggerated motion or insufficient propulsion from a locomotive unit, shock absorption, stance stability and energy conservation.
Core postural muscle stability is suspect upon extreme drops of pelvis crest and pelvic rotation is detected. This simply calls for more tests upon gluteal muscle function in open and closed kinetic chain positions. A significant observation would also be excessive hip adduction with knee valgus, producing an increased dynamic quadricep angle. Knee varus thrust, expressed as lateral knee shift may be indicative of lateral knee complex instability or osteoarthritis of the medial knee compartment. Early heel rise during propulsion is a common compensation for hallux limitus, sesamoiditis, or ankle equinus.
Dananberg and Guiliano describes a relationship between hallux limitus and spine pain and co-relates it to deficient hallux extension in late stance phase during walking. Contralateral increased lateral shift is described as the lower extremity adapting to the loss of hallux extension with the concomitant decrease in hip extension at midstance. Spine pain patterns are related to the hallux limitus, and Dannenberg and Guiliano describe a 36% improvement with custom foot orthotics described to neutralize deleterious effects of hallux extension loss (Deppen, 2007).
The use of objective measurement tools is swiftly overtaking self-made assessments of physical activity. Data collection techniques such as questionnaires or diary logging are fast turning obsolete since the accuracy of data produced far outweighs these traditional methods. Accelerometers currently possess a widespread usage within research communities in conducting population-level studies to assess health and performance. The seemingly inconspicuous wrist-worn devices allow not only accurate data to be collected but uncovers a greater, more wholesome coverage of movement analysis or physical activity in the user’s habitual space, without the risk of self-report bias. All in all, making this a more convenient and hassle-free data collection tool.
Critical Analysis of Literature
To begin with an in-depth analysis on the text, the focus first gives attention to the planes of motion which consolidates an important basis of human movement analysis.
The sagittal plane passes from the posterior to the anterior of the body, with a vertical line running through that divides it into left and right halves. Flexion and extension of limbs as well as the movement for dorsiflexion and plantarflexion occurs here.
Similarly, the frontal plane uses a vertical line, but passes from the left side to the right of the body. Abduction, movement away from midline of the body, and adduction, movement towards midline of the body, occurs here. Additionally, inversion, rotation of the sole of the foot towards the midline of the body, and eversion, rotation of the sole of foot away from the midline, also occurs in this plane.
Lastly, the transverse plane divides the body into superior and inferior halves. Supination, rotation of the forearm and hand, such that palm faces forward or upward; also refers to a corresponding movement of the foot and leg in which the foot rolls outward with an elevated arch and pronation, rotation of hand and forearm such that palm faces backward or downward and another corresponding movement of the leg where the foot rolls inward (Webster, 2004), occurs here.
These 3 respective planes and axes of rotation are vital in assessing movement accurately.
Next, following through on Deppen’s study in Sports Specific Rehabilitation (2007), in relation to gait analysis and more specifically, foot pronation/supination.
Deppen states that, excessive foot pronation could be caused by three potential observations: Excessive calcaneal eversion, Medial midfoot collapse and Excessive toe out.
Abnormal foot supination is potentially caused by calcaneal inversion, excessive medial midfoot arch height and disproportionate weight bearing on the lateral foot. First and fifth metatarsal heads may develop large callus formation.
Excessive toe-out posturing in stance phase may represent compensation for hallux limitus, ankle equinus, excessive tibial external torsion, or excessive foot pronation. Toe-out walking patterns place increased medially directed elongation stresses and laterally directed compressive stresses along the soft tissues of the ankle joint.
Gait assessment of running includes all of those previously described with attention given to initial foot strike. First foot contact may be observed at the calcaneus, midfoot, forefoot, or toes. Early-stance phase heel strike enables ankle joint dorsiflexion and foot pronation to provide weight-bearing loading and shock absorption. Forefoot and toe strike as the initial foot contact is the norm in running sports’ requirement for speed and change of direction. Prolonged straight-ahead running with forefoot and toe strike as the initial contact relates to decreased shock absorption capability (Deppen, 2007).
Movement analysis would certainly not have been as accurate or in-depth as the gait assessment if not for the usage of objective measurement tools. However, techniques like 3D motion capture requires a meticulous set up prior to usage, with thorough camera calibration to ensure accuracy in measurement and consistency. Performance of these systems strongly depends on their setup and is highly sensitive against alterations (Morlock, Windolf, ; Gotzen, 2008).
Thus, lengthy set up times, human error in marker placement and high cost could make it a tedious and difficult process.
3D Motion Capture require several specifics but does not require as much space as the use of force plates. To ensure maximum accuracy and provide real time data when individuals are performing activities such as counter movement jumps, drop jumps and single leg balances. Multiple force plates can be set up to allow gait assessment through the calculation of contact time, flight time and stride frequency.
Marker-less depth cameras, smartphones and smartwatches bring forth the latest revolution in technology that should enable a more convenient form of methodology in data collection that will quicken experimental procedures. Through portability and accessibility, these handy means of assistance offer security, big-data collection and even allows practitioners a means to carry out movement assessment with minimal set-up. However, it must be noted that these tools are not entirely validated and will affect the overall validity in an assessment.
In 2D video analysis, preparation involves learning the technique to be analysed and gaining an understanding of the components that form the movement. Next, through observation, this concerns the set-up process that one must follow to ensure the quality of capture is as accurate as possible and provide the necessary data.
Analysis of performance should involve ensuring any errors identified can be remedied and will not negatively impact other component parts.
Finally, one should consider the most appropriate type of intervention, like timing and frequency of the feedback, which is influenced by the complexity of the skill or level of performer and timescales involved. All in all, a potentially tedious and complicated process