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 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 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. 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.
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, a bottom-up approach is preferred, 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.
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 (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.
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; and pronation, rotation of hand and forearm such that palm faces backward or downward (Webster, 2004), occurs here.
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.
Gait assessment of running includes all of those previously mentioned 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 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
Recommendations for Applied Use
Besides figuring out the limitations of subjective movement screening techniques and how this affects results produced, how it can be used as a means of improvement to an athlete’s attributes in terms of mobility, flexibility and stability amongst some of them which might aid them in sports specific movements.
Clinical single-camera videotaping during observational gait analysis provides a significant tool both for assessment and patient instruction. Video captures 60 images/second compared with the naked eye, which only captures 4 to 6 images/second. Immediate playback provides pause frame and advance abilities enhancing clinical study and patient feedback (Deppen, 2007).
Instrumented gait analysis systems include motion analysis, dynamic electromyography and force plate measurement. Motion analysis systems are designed to define the magnitude and timing of individual joint action. Dynamic electromyography provides muscle function data defining timing and contraction intensity. Force plate systems measure weight-bearing loading characteristics.
For objective measurement tools, depth camera technology offers a cost-effective alternative to motion capture systems and has less chance of human error due to its marker-less nature. Furthermore, with respect to Kinetic technology, it can be used as a home-based tool by Parkinson’s Disease and stroke patients to help assess normalised stride length (Cao et al., 2017).
The most accurate and practical manner of using 2D video analysis would be in providing observational feedback with respect to athletic performance and team tactic. By accurately capturing observations, the strive for physical or tactical perfection can be accomplished.