Kinetic Precision Study

kinetic precision study 2014

copyright 2014

View PDF Here: Kinetic precision study 2014 Copyright

Introduction

Exercises should be performed correctly in order to ensure the correct muscles are used and activated. Unfortunately for various reasons exercisers do not always perform a movement or exercise correctly and as a result the individual does not get maximum benefit from the exercise. According to Thompson (2014), when a muscle is in a constant eccentric state, in relation to its antagonist, it becomes inhibited in its concentric state. In order for the limb to move to the supposed agonists’ concentric state, synergists for the movement dominate the movement inhibiting the agonist even more both muscularly and neurologically. Correct exercise technique and form is essential to overcome this effect. Everyday actions that contribute to this effect includes:

  • Sitting to standing; the gluteus maximus is required to work from an eccentric towards a concentric position to get us to into the normal standing position, the concentric activation of the muscle is very important as this is the natural movement that is required in order to facilitate a stabilized movement. However, most of the population rely on the use of their arms to get them to that daily standing position. This is a functional movement and therefore should be performed effectively.

 

  • Gait; there should be a certain amount of effort exerted from the gluteus maximus in the gait cycle, especially on the heel phase of natural gait, and this should be continued through to a certain degree as the hip goes into extension. The gluteus maximus will aid in stability of the sacral region during gait as the gluteus medius maintains stability in the pelvis and hips and therefore the lumbar spine, avoiding the lateral flexion action that might occur should the gluteus medius not work sufficiently

(Thompson, 2014). However, the gluteus medius is often hypo-active and therefore the synergists are likely to become dominant i.e. Tensor Facia Lata. This could be contraindication for the knee joint, should this compensation or altered stability pattern persist.

A strong mind-body connection during exercise training and the appropriate instruction, using very specific techniques, will positively influence the results achieved from an exercise.

Ensuring the correct muscles are activated effectively and overcoming the above stated effect, the exerciser gains maximum benefit from the training leading to more effective long term results (Thompson, 2014).

Primary objective

The primary objective of this project was to determine if various muscles could activate more effectively as well as eliminate possible compensations by applying the specific analysis of movement and incorporating this in the instruction as per the Kinetic Precision technique, as opposed to no or minimal instruction based on a general trend of instruction that exists within the industry. The “Kinetic Precision” method included placing the body in a favourable position and using “Conscious Initiated Muscular Resistance” whereby an antagonist of the primary mover or an antagonist which would inhibit the compensation of occurring would be consciously activated in order to increase the activation in the primary mover. This activation would be minimal but the results of the primary mover would either increase or decrease depending on the desired outcome.

Hypothesis

There would be increased or decreased (depending on desired outcome) muscle activation of a specific muscle during the same movement or exercise when performed while receiving instructions (“Kinetic Precision” technique) as opposed to no or minimal instruction.

Subjects

Twenty (20) voluntary subjects participated in this study. Subjects completed an informed consent and pre-participation screening form before commencing the study. Subjects were recruited via word of mouth.

Inclusion criteria:

  • Age: 18 – 30 years of age,
  • Gender: Females and males,
  • Fitness Level: Recreationally active.

Exclusion criteria:

  • Musculoskeletal injuries specifically of the shoulder and hip region,
  • Currently following a structured exercise programme,
  • Taking medication that could influence response to the exercise,
  • Any medical condition that puts them at risk during exercise.

Equipment and facilities

Assessments took place at the Institute for Sports Research (ISR) testing laboratories.

Ethics

Before the commencement of the study the research protocol was submitted and approved by the Ethics Committee of the Faculty of Humanities at the University of Pretoria.

Protocol

Various movements or exercises (Table 1) were performed by the subjects firstly on their own with general instruction and then again after being instructed with a specific technique

(“Kinetic Precision” technique). The movements or exercises were performed while surface electromyography (EMG) measurements were taken for 2 different muscles during an exercise. It was either the primary mover versus the compensatory muscle or the muscle that will inhibit the compensation. EMG data was collected and analyzed using Noraxon,

EMG & Sensor Systems (Scottsdale, Arizona) using standard EMG techniques and protocols.

Data Analysis

The Wilcoxon Matched Pairs Test was used to determine if there was a difference in terms of the muscle activations when the movements or exercises were performed on their own and then with instruction (“Kinetic Precision” technique). The statistical analysis was conducted using STATISTICA 12. All statistical tests were conducted using the conventional

5% level of significance.

Exercises or movements performed and muscles tested using Electromyography (EMG) 

Exercise Primary Muscle Additional muscle Load

Side lying Gluteus maximus M. Gluteus maximus M. Erector spinae (lumbar) Low

Description of exercise: The subject lay on his/her side with their body at a 30° angle off of the wall and their right hip (top hip) in slight hip flexion as well as knee flexion. The left leg (bottom leg) was in 90° hip and knee flexion on the floor.

The subject was then instructed to press their right foot into the wall (closed chain) and slightly abduct the leg to activate the gluteus maximus.

  • Knee extension sitting M. Rectus femoris M. Erector spinae (lumbar) Low

The subject was sitting on a block that enabled the hip to be just below approximately 90°. The subject was then instructed to lift the right leg slightly off of the floor. They were then required to extend the knee in order to activate the rectus femoris. They were then required to flex the knee back to the starting position.

  • Side lying Glute Medius M. Gluteus medius M. Tensor facia latae Low

The subject was lying on their side with their left knee and hip flexed at approximately 90° and the right leg extended at the knee and hip. They were required to maintain the left oblique lifted off of the floor and were then asked to raise the right leg up by using the hip abductors. After which they lowered the leg back down.

  • Sitting Arm Flexion M. Deltoid (Anterior) M. Trapezius (upper) Low

The subject was sitting on a block so that the hips were flexed at approximately a 90° angle. The right arm was relaxed at their side holding a theraband. They were then instructed to raise their arm into shoulder flexion. After which the arm was returned back to the starting position.

  • Sitting Theraband M. Infraspinatus M. Trapezius (middle) Low

The subject was sitting on a block so that their hips were flexed at approximately a 90° angle. The subject held a blue theraband in a supinated forearm position whilst the instructor held the theraband on the opposite side in order to stabilize the theraband. The subject then had to laterally rotate the shoulder and then to return to the starting position.

  • Back extension prone on Ball M. Erector spinae (thoracic) M. Erector spinae (lumbar) Low

The subject was asked to lie supine over a 65cm ball with the pelvis towards the back of the ball. The feet were anchored against the wall. The arms were placed at a low V position near the hips. The subject was then instructed to raise their thoracic spine off the ball in order to activate the back (thoracic) extensors. They then returned to the starting position.

  • Supine Bridge M. Gluteus maximus M. Biceps femoris Low

The subject was lying supine on a mat. The feet were placed on a wooden box that was approximately 30cm off of the floor and the knees were bent at a 90° angle. The subject was instructed to raise their pelvis off the floor, thereby executing hip extension. They then returned to the starting position.

Results:

Table II. The mean, minimum, maximum and standard deviation of the muscle activation (μV) for the various movements / exercises

 KP results

Table III. Difference between movement or exercise 1 (without instruction) and movement or

exercise 2 (with instruction – Kinetic Precision)

Movement/ exercise Muscle Difference (p-value)

KP results 2

Table IV. Desired effect of “Kinetic Precision” instruction vs. results

Exercise Primary Muscle Additional muscle Load

  • Side lying Gluteus maximus M. Gluteus maximus M. Erector spinae (lumbar) Low

Desired effect: Increasing the activation of the M. Gluteus maximus with the M. Erector spinae activation staying the same or decreasing by implementing “Conscious Initiated Muscular Resistance”. Thus increasing the activation of the lower Rectus Abdominis in order to inhibit the M. Lumbar Erector Spinae as well as place the pelvis in a favourable position.

Results:

  1. Gluteus maximus: Activation increased from 61.6 – 91.5μv (p_0.05)_ (Desired effect achieved and significant)
  2. Erector spinae (lumbar): Activation increased from 22.7 – 29.2μv (p_0.05)_ (Desired effect not achieved and significant)

 

  • Knee extension sitting M. Rectus femoris M. Erector spinae (lumbar) Low

Desired effect: Increasing the activation of the M. Rectus femoris by increasing the contraction of the M. Erector spinae (lumbar) by means of “Conscious Initiated Muscular Resistance”.

Results:

  1. Rectus femoris: Activation increased from 96.2 – 137.4μv (p_0.05) (Desired effect achieved and significant)
  2. Erector spinae (lumbar): Activation increased from 16.7 – 19.4μv (p_0.05) (Desired effect achieved and significant)

 

  • Side lying Gluteus medius M. Gluteus medius M. Tensor facia latae Low

Desired effect: Increased activation of the M. Gluteus medius by making the subject more aware of the positions and muscles involved in executing the exercise efficiently and eliminating compensations.

Results:

  1. Gluteus medius: Activation increased from 74.28 – 116.0μv (p_0.05)_ (Desired effect achieved and significant)
  2. Tensor fascia latae: Activation decreased from 125.9 – 95.6μv (p>0.05) (Desired effect achieved but not significant).

 

  • Sitting Arm Flexion M. Deltoid (anterior) M. Trapezius (upper) Low

Desired effect: Increased activation of the M. Deltoids (anterior) while maintaining shoulder stability by means of specific cues by the instructor and a possible decrease in M. Trapezius (upper) activation.

Results:

  1. Deltoids (anterior): Activation decreased from 525.3 – 509.7μv (p>0.05) (Desired effect not achieved but not significant)
  2. Trapezius (upper): Activation decreased from 154.3 – 101.5μv (p_0.05)_ (Desired effect achieved and significant)

 

  • Sitting Theraband M. Infraspinatus M. Trapezius (middle) Low

Desired effect: Increased activation of the M. Infraspinatus with less activation of the M. Middle trapezius this can be achieved by mind body connection to disassociate the shoulder.

Results:

  1. Infraspinatus: Activation decreased from 525.3 – 509.7μv (p>0.05)_ (Desired effect not achieved and significant)
  2. Trapezius (middle): Activation decreased from 154.3 – 101.5μv (p_0.05)_ (Desired effect achieved and significant)

 

  • Back extension prone on Ball M. Erector spinae (thoracic) M. Erector spinae (lumbar) Low

Desired effect: Increased activation of the M. Thoracic erector spinae with less activation of the M. Lumbar erector spinae as this encourages efficient posture. This was attempted by means of activating the M. Rectus abdominis in order to maintain a posterior tilt in the pelvis.

Results:

  1. Erector spinae (thoracic): Activation increased from 52.0 – 58.01μv (p_0.05) (Desired effect achieved but not significant)
  2. Erector spinae (lumbar): Activation decreased from 37.1 – 31.3μv (p_0.05) (Desired effect achieved but not significant)

 

  • Supine Bridge M. Gluteus maximus M. Biceps femoris Low

Desired effect: Increased activation of the M. Gluteus maximus with less activation of the M. Biceps femoris by means of closed chain work for the Gluteal muscles as well as closed chain eccentric M. Quadriceps contraction.

Results:

  1. Gluteus maximus: Activation increased from 24.5 – 69.8μv (p>0.05)_ (Desired effect achieved and significant)
  2. Biceps femoris: Activation decreased from 48.6 – 41.8μv (p_0.05)_ (Desired effect achieved and significant)

 

Discussion and Conclusion

There was a significant difference (p_0.05) in terms of muscle activation between test one and test two for ten of the fourteen muscles tested using surface EMG. Namely, Side lying

Gluteus maximus exercise (M. Gluteus maximus and M. Erector spinae – Lumbar), Sitting knee extension exercise (M. Rectus femoris and M. Erector spinae – Lumbar), Side lying

Gluteus medius exercise (M. Gluteus medius), Sitting Arm flexion exercise (M. Trapezius – upper), Sitting Theraband exercise (M. Infraspinatus and M. Trapezius – middle) and Supine bridge exercise (M. Gluteus maximus and M. Biceps femoris). For all the significant differences (p_0.05), test 2 (with instruction – Kinetic Precision) was greater in terms of muscle activation except for the Sitting Arm Flexion Exercise (M. Trapezius – upper), Sitting

Theraband Exercise (M. Trapezius – middle) and Supine Bridge Exercise (M. Biceps Femoris).

The desired effect with regards to muscle activation increasing OR decreasing significantly

(p_0.05) was achieved in eight muscles. The desired effect occurred in an additional three muscles however the effect was not significant (p>0.05). (Please refer to Table 3). Thus the desired effect was achieved in 79% (11/14) of the muscles tested although not all significantly (p_0.05).

Therefore results appear promising regarding the effects of “Kinetic Precision technique using Conscious Initiated Muscular resistance” in terms of exercise form and muscle activation. Mindful training in order to obtain an effective contraction in agonists whereby you are able to eliminate compensatory muscles may be useful. New muscular patterns could be re-educated through consistent repetition over a short or long period of time.

More significant results could possibly be achieved if the effects of increasing mind-body connection and exercise technique by means of “Conscious Initiated Muscular resistance” was assessed over time by means of regular comprehensive instructions and explanations of exercise technique and form. In addition, further research is recommended using a larger sample and possibly comparing various instruction techniques using a cross-over design (acute study).

References

Thompson, T. Kinetic Precision Document. 2014

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