kin3347group-blog - Tumblr blog

[kin3347group-blog]

Introduction

The performed skill was a skipping movement with a jump rope. A running motion was added to the skill to allow for proper analysis of balance, coordination, and locomotion. The participants held an end of the rope in each hand and used the glenohumeral and radiocarpal joints to rotate the rope up and over their head while alternating their body weight between their feet. This movement required coordination to complete both the running and jumping motion, balance to ensure that the individual did not trip over the rope, and locomotion to be able to run in one place.

The movements of the lower body for this skill can be divided into three phases. The first phase is called the loading phase during which one leg flexes at the hip and at the knee while the contralateral leg remains planted on the ground. This motion results in one leg elevated as the other supports the weight of the body and maintains the centre of gravity. At the same time, the glenohumeral and radiocarpal joints begin to circumflex to swing the rope forward; this motion continues throughout the three phases. As the rope approaches the ground, the planted leg bends to prepare for flight, creating tension in the muscle fibres (Pitreli and O’Shea, 1986).

The second phase is called the flight phase, where the whole body is in the air without support. This phase begins when the planted leg is activated in an explosive movement, pushing away from the ground into a brief airborne state. During the airborne state, the rope passes under the legs and begins to rotate up and overhead (Pitreli and O’Shea, 1986).

As the rope rotates behind the individual, the flexed leg extends and reunites with the ground. This third phase is called the landing phase as it is the portion of the movement when the foot reconnects with the ground, establishing balance and enabling the movement to begin again with loading (Pitreli and O’Shea, 1986).

Word count: 319

[kin3347group-blog]

undefined

Early Childhood, 2-6 

This video features Cooper, a three year old boy.

During early childhood (age 2-6), the child is not able to coordinate complex actions or perform fine movements with precision. Individually, the three year old is able to run, jump, gallop, step over the rope and duck under the rope. However, there is a lack of integration and coordination between all of these skills that would enable the child to run and skip rope simultaneously. This video displays that the early child may have difficulties with coordination, locomotor awareness, and fine motor movement.

The lack of coordination between movements can be attributed to various patterns of motor development. The three year old is likely undergoing myelination at the neural level, a process that will not be complete until the child’s early 20’s (Boyd et al., 2018). Cooper is in the early stages of myelination, and as a result is not able to properly coordinate fine movements or complex gross movements (i.e. running, galloping, and moving the rope). A 2000 study by Adele Diamond presents the idea that the development of the cerebellum and the dorsolateral prefrontal cortex are main contributors to motor and cognitive advancements throughout childhood. Applying this research, it can be reasoned that Cooper’s cerebellum and dorsolateral prefrontal cortex may not be fully myelinated, resulting in poor balance, conduction speed, and task retention. The child displays poor locomotor skills throughout the movement as he is not yet able to complete all of the skills collaboratively. This is evident when the child becomes tangled in the rope when trying to skip and run simultaneously, and when he doesn’t display a consistent direction (forwards or backwards) of the skipping rope.

The early child also moves with his whole body, focusing on gross motor movements. For example, the child ducks under the rope using his trunk rather than rotating at the radiocarpal joint and glenohumeral joint to revolve the rope above his head. The three year old also has difficulty with grasping the skipping rope handles, holding one by the top and one by the base, showing no attention to the fine motor grasp needed to properly skip. The child may be performing the movements in this way as a result of typical cephalocaudal and proximodistal development patterns with myelination (Boyd et al., 2018). It is easier for the child to perform a whole body sequence rather than a body component sequence that involves more distal muscles and joints (Malina, 2004).

Due to the inability to sequence several movements into the skill, it is difficult to identify where the three phases of the skill begin and end. As the child progresses through the myelination process, he will be able to perform and apply more advanced fine motor movements (i.e. grasps) and body component sequences to integrate movements.

Word count: 446

[kin3347group-blog]

undefined

Middle Childhood, 6-12 

The video features Chenchen, a 7-year old girl.

Throughout later childhood (age 6-12), large-muscle coordination, muscle strength, and speed continues to improve; enabling children to perform activities that require advanced skills. Compared to males, females have an advantage in overall development due to faster muscular and skeletal maturation (Boyd et al., 2018). Females also develop faster in fine motor skills as a result of faster growth in wrist structures (Boyd et al., 2018). The myelination of the brain develops rapidly and predominantly in the sensory and motor areas, leading to significant improvements in hand-eye coordination (Boyd et al., 2018).  

Chenchen is able to demonstrate the skill from start to finish, suggesting significant improvement from early childhood. During the loading phase, her weight-bearing leg is in slight hip and knee flexion, while her torso flexes towards her legs. This forward flexion of the torso rather than upward flexion of the limbs is characteristic of whole body sequencing as opposed to partial body segmentation (Boyd et al., 2018). As proximodistal and cephalocaudal development continues to proceed, she will become more efficient with flexion of the correct body segment.

In the flight phase, Chenchen uses her whole body’s strength and jumps higher than necessary. At the same time, she runs forward instead of staying in one place, similar to the observation of Cooper in the early child. During the landing phase, she balances on the single limb and stabilizes her torso before initiating another loading phase to continue the skill. This results in a longer landing phase relative to the other two phases, making the rhythm of the skill less balanced. She also continuously looks at her feet in an attempt to maintain balance.

Although fine motor coordination starts to improve during later childhood, Chenchen’s wrist structure is not strong and skillful enough to handle the subtle forces of rotation. As a result, she rotates the rope by whole-arm circumflexion at the shoulder rather than at the forearm and the wrist to control the rhythm of rope rotation.

All of the behaviours demonstrated in this video could be explained by the fact that she is at the beginning of later childhood. Therefore her fine motor skills, hand-eye coordination, and locomotor skills are in the early stage of development (Boyd et al., 2018). In conclusion, the overall performance requires more effort and proceeds at a slower pace.

Word count: 373

[kin3347group-blog]

undefined

Adolescence, Age 12-18 

This video features Daniel, an 18 year old boy

Puberty is a term used to describe the physical and hormonal changes that are required for reproductive maturity. The onset of puberty varies widely, however, girls who are early developers can show signs of puberty as early as age ten (Boyd et al., 2018). During adolescence (age 12-18), individuals notice dramatic changes in growth rate approaching 5-13 centimeters of height per year for several years (Boyd et al., 2018). Joint development during this time allows adolescents to achieve coordination similar to that of an adult, aiding Daniel to jump rope effortlessly. In the early stages of adolescents, females have greater gains in fine motor skills when compared to their male counterparts (Boyd et al., 2018). By the age of 17-18 males surpass females in joint development and gain superiority in coordinated movement. (Davies et al., 2000)

During growth spurts the regular cephalocaudal and proximodistal patterns are reversed; the hands and feet are therefore the first body parts to reach full maturity. Asymmetrical growth in teens often stereotypes them as awkward, however this assumption is incorrect as they continually develop coordination skills through this phase (Boyd et al., 2018). A study has shown that there was no evidence of impaired coordination or “awkwardness” through the pubescent period of development (Davies et al., 2000). The ability to coordinate the jumping motion at the correct time to clear the rope is especially important when the subject transitions from the loading phase to the flight phase of the skill. Additionally, adolescent males will experience a decrease in body fat and an associated increase in muscle density. Females in this stage will notice the reverse effect as body fat increases and muscle density declines. This gender difference in muscle density and associated strength is a result of hormone changes (Boyd et al., 2018).

When compared to his female peers, Daniel may notice a more rapid increase in physical speed, jumping strength, throwing strength, and endurance through this period of growth (Davies et al., 2000). Muscle fibres throughout adolescence become thicker and stronger leading to increases in strength (Boyd et al., 2018). These developments allow Daniel to utilize the type I fibres in his quadriceps, hamstrings, calf muscles and glutes to perform the explosive jumping movement during the flight phase. Daniel has the ability to maintain a stable core and upright posture while using his radiocarpal joint and glenohumeral joint to rotate the rope above his head.

In addition to developments in musculature and height, teenagers experience considerable growth in heart and lungs resulting in a decreased heart rate. Due to increased aerobic endurance he will be able to maintain physical efforts longer than girls of the same age (Boyd et al., 2018). Daniel will be able to continue the skipping skill longer than children in younger developmental phases and adolescent girls. This is a stage of development where a dramatic amount of growth occurs allowing an individual to perform this skill with more ease.

Word count: 495

[kin3347group-blog]

undefined

Early Adulthood, 19-59 

This video features Songlin, a 21-year old university student (female).

     In early adulthood (age 19-59), the physical capacity (i.e. the muscular system and cardiovascular system) is generally at its best state to meet all physical demands (Boyd et al., 2018). Although the brain, especially the prefrontal cortex, continues to develop into adulthood. In addition, sensory and motor functions have been fully lateralized in early adulthood(Boyd et al., 2018). These advancements in neural functioning allow for the subject to sequence the movement perfectly and with ease.

        Songlin’s entire body is in an upright position with the centre of gravity shifting downward during the loading phase, preparing for the following countermovement jump. She jumps to a height that is just right to clear the rope consistently throughout her performance. In the landing phase, she lands on the extended leg with forefoot technique while her take-off leg flexes toward the torso. This allows for better shock absorption and smoother transition to the next loading phase. The three phases are closely connected with each other and flow with a good rhythm. In addition, she keeps her upper limbs steady, using her forearms and wrists to rotate the rope around her body. Her fully developed wrist structure and fine motor skills make it possible for her to control rope rotation with minimal effort and disturbance to the body.

      Songlin’s fully developed muscles and neuromuscular function enable her to perform the motor skill of jumping rope without difficulty or error. The skill is performed consistently at a fast pace, suggesting that the eye-hand-foot coordination is fully developed. Muscle strength, Power, and joint proprioception is also fully developed, enabling her to locomote with ease and maintain balance throughout the skill. The type I muscle fibres (e.g. calf muscles, quadriceps, hamstrings, gluteus, abdominal muscles) function to keep transient balance on a single leg and quickly stabilize her upper body during continuous movement. The type II muscle fibres (e.g. calf muscles, quadriceps, hamstrings, gluteus) in her lower limb provide the power for vertical jump on a single leg.

Songlin’s ability to perfectly perform the skill supports Boyd et als’ claim that “Compared with older adults, adults in their 20s and 30s have more muscle tissue; maximum bone calcium; more brain mass;....” (2018). In the next section, this comparison is evident as the early adult is stronger, faster, and more consistent than an older adult (Boyd et al., 2018).

Word count: 387

[kin3347group-blog]

undefined

Older Adulthood, 60+ 

The video features Mike, a 61-year old active male.

The chosen skill was predicted to be more challenging for an older adult (age 60+), as there would be increased difficulty with systems that deteriorate with age, such as balance and coordination. The main areas of the brain that are affected with age are the motor cortical regions and the corpus callosum (Seidler et al., 2010). The cerebellum also undergoes atrophy, prominently in men, which is the main region of the brain involved in balance and coordination (Hogan, 1970). Declines within these regions are directly associated with declines in balance, gait, coordination, and movement speed (Seidler et al., 2010). The decline is due to the decrease in functioning of the sensory receptors, muscles, and peripheral nerves within the body (Seidler et al., 2010). For example, much like the synapse pruning that occurs in the first few years of life, there is a loss of dendrites and a decrease in the dendritic connections in older adulthood (Boyd et al., 2018). There is a degeneration of grey matter and nerve fibers in white matter, therefore causing disconnections within the nervous system to the peripheral systems (Peters, 2009). This degeneration ultimately affects older adults’ ability to perform movements with high coordination (Peters, 2009).

Another change within the aging body is the postural adaptations, which ultimately leads to balance declines. As people gets older, they begin to develop a more kyphotic posture, which is an excessive convex curvature within the thoracic and sacral regions of the spine (Woodhull-McNeal, 1992). This excessive convex curvature forces the hips to shift posteriorly, which causes more forward lean from the hips (Woodhull-McNeal, 1992). Consequently, the center of gravity also shifts more anteriorly, which causes more balance issues for the subject as he performs the skill (Woodhull-McNeal, 1992).  

The analysis of the chosen skill by the 61-year-old male supports many of these previously studied findings. Firstly, it is clear that the individual has trouble coordinating the movement in all three of the movement phases. He has to stop the running-skip motion in the landing phase to regain his balance/coordination, and then he restarts the movement once this is gained. This loss in balance/coordination during the landing phase is demonstrated by the rope getting caught between his feet within the running-skip motion. He also proves that coordination and balance is challenging for him during the initial performance of the movement, as he can only do the running-skip motion properly at a slow speed.

In addition, the 61-year-old is also particularly active in his older adulthood, therefore this will decrease the amount of muscle fiber degeneration, and assist his balance and coordination. Many individuals are also able to perfect a movement or skill if they practice it, which is also clear in this video. The individual demonstrates this at the end of the video when he runs down the street and turns around while skipping without tripping over the rope or having to stop the movement. Through the analysis of the older adult it is obvious that there are challenging aspects to the performed skill, such as balance and coordination.

Word count: 483

[kin3347group-blog]

Conclusion 

  Skipping rope with a running motion is a coordination skill that is observed to improve over human development, but eventually declines in older adulthood. Throughout the three phases there were varying differences between each age group.

The participant in early childhood struggled the most with the motor planning of this skill. The child failed to integrate fine motor movements and focused excessively on entire body sequencing, while demonstrating a lack of coordination and balance.

In later childhood, the participant began to show signs of fine motor coordination development, but she still used her whole arms to rotate the rope instead of solely her wrists. The individual was able to perform the skill from beginning to end but overestimated the height needed to clear the rope. She also spent more time on the ground before initiating another cycle through the three phases of the movement, as she had difficulty maintaining her balance.

The subject in the adolescent phase demonstrated the skipping skill comfortably with increased speed, and increased ability to coordinate the height of the jump. Regardless of the dramatic structural growth during this age period and reversed growth pattern that exists in the adolescent phase, the individual still demonstrates increased strength, power, and endurance.

The individual in early adulthood optimally performed the skill and had no difficulties. Contrastly, the individual in older adulthood began to decline in the performance of the skill, as the subject had more difficulty balancing on one foot during the loading and landing phases of the skill. The participant in older adulthood performed the skill with declined coordination, as neural degeneration increases with age.

To conclude, the findings demonstrate a parabolic relationship across the development of the performed skill. However, the sample size for this study is noticeably small, therefore, it is challenging to conclude concrete findings. Futuristically, we would compare a larger sample size of each age group with varying genders to analyze the specific balance, coordination and locomotion difficulties that may vary from individual to individual.

Word count: 332

[kin3347group-blog]

Citations

Boyd, D., Johnson, P., & Bee, H. (2018). Lifespan Development, Sixth Canadian Edition. Don Mills, Ontario: Pearson Canada Inc.

Davies, P., & Rose, J. (2000). Motor Skills of Typically Developing Adolescents. Physical & Occupational Therapy In Pediatrics,20(1), 19-42. doi:10.1300/j006v20n01_03

Diamond, A. (2000). Close interrelation of motor development and cognitive development and     of the cerebellum and prefrontal cortex. Child Development, 71(1), 44-56. Doi:10.1111    /1467-8624.001173

Hogan, M. (1970, March 1). The Importance of Cerebellum for Intelligence and Age-Related

Cognitive Decline. Retrieved from https://www.memory-key.com/research/news/importance-cerebellum-intelligence-and-age-related-cognitive-decline

Malina, R.M. (2004). Motor development during infancy and early childhood: Overview and    suggested directions for research. International Journal of Sport and Health Science, 2,      50-66. Doi: 10.5432/ijshs.2.50

Peters, A. (2009). The effects of normal aging on myelinated nerve fibers in monkey central

nervous system. Frontiers in Neuroanatomy, 3. doi:10.3389/neuro.05.011.2009

Pitreli, J., & Oʼshea, P. (1986). SPORTS PERFORMANCE SERIES: Rope Jumping: The biomechanics, techniques of and application to athletic conditioning. National Strength & Conditioning Association Journal,8(4), 5. doi:10.1519/0744-0049(1986)0082.3.co;2

Seidler, R. D., Bernard, J. A., Burutolu, T. B., Fling, B. W., Gordon, M. T., Gwin, J. T., . . .

Lipps, D. B. (2010). Motor control and aging: Links to age-related brain structural, functional, and biochemical effects. Neuroscience & Biobehavioral Reviews,34(5), 721-733. doi:10.1016/j.neubiorev.2009.10.005

Woodhull-McNeal, A. P. (1992). Changes in posture and balance with age. Aging Clinical and Experimental Research, 4(3), 219-225.