How Repeated Stretches Affect Muscle Viscoelasticity

How Repeated Stretches Affect Muscle Viscoelasticity

Dr. GJohn Mullen Biomechanics, Blog, Dr. John Mullen, Latest&Greatest, Training Leave a Comment

Viscoelasticity is the ability to return of a material to return to a position after an extended force application. Dynamic tissues (muscles, tendons, ligaments) possess viscoelastic structures. The ideal mechanism and benefits of stretching are uncertain, but previous work suggests constant-torque is more beneficial than constant-angle for improving muscle creep, resulting in a decrease in stiffness. This creep is the …

Effect of Squat Depth and Load on Muscular Effort

Effect of Squat Depth and Load on Muscular Effort

Dr. GJohn Mullen Blog, Competition, Dr. John Mullen, Dryland, Latest&Greatest, Training Leave a Comment

The squat is a popular dry-land exercise for swimming. This is likely due to the numerous muscles involved and the common belief this motion mimics a flip turn (despite contradictory research). However, the effect the depth and load on the squat are unknown. Muscle force is hard to measure, therefore motion analysis techniques combined with the equations to solve for …

Variation in Body Center of Mass During Freestyle

Variation in Body Center of Mass During Freestyle

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Body position is deemed an important variable for swimming success. However, body position is typically regarded as a static position in freestyle, despite noticeable undulation during the swims of many elite middle-distance swimmers. Perhaps more importantly, external work depends on changes in the position and velocity of the center of mass (CM), which is typically expressed as the intracycle velocity variation …

Kinematics of the Thoracic Spine in Trunk Rotation

Kinematics of the Thoracic Spine in Trunk Rotation

Dr. GJohn Mullen Biomechanics, Blog, Dr. John Mullen, Latest&Greatest, Training Leave a Comment

Thoracic spine rotation is used in long-axis swimming. Therefore, understanding the biomechanical demand of this motion is mandatory to understand the optimal hydrodynamics. Unfortunately, the thoracic spine is rarely researched due to the low volume of injuries at this region. Simply comparing the thoracic spine to other areas is unjust, as the thoracic spine has many differences from the rest …

Shoulder Kinematics During Scapular Plane Abduction

Shoulder Kinematics During Scapular Plane Abduction

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Shoulder impingement is the most common injury in swimming. Many factors contribute to shoulder impingement and one is inadequate space for clearance of the rotator cuff tendons during arm elevation. Previous studies have analyzed healthy shoulder range of motion with single-plane radiographs, but did not provide 3-D motion of the shoulder. Three-dimensional analyzes are necessary to understand the activity in …

Minimizing Central Motor Control Breakdown

Minimizing Central Motor Control Breakdown

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Any repetitive task results in performance impairments over time. The cause of these decrements is typically considered physiologically induced. However, recent studies and exercise physiologist feel these impairments are influenced by the central nervous system. Transcranial magnetic stimulation (TMS) is suggested to alter the excitation of the movement areas in the brain (corticomotor tracts). The limits of maximal voluntary rate …

Auditory feedback helps adapt to altered environment

Auditory feedback helps adapt to altered environment

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Providing feedback during practice and competitions is common in all sports. Despite the difficulty of providing feedback during swimming, coaches and teammates commonly provide numerous visual and auditory cues. Sensory substitution is the skill of the nervous system to receive input from one sensory system and transmit this information to another sensory system. For example, in swimming the sensory system …

Posterior Capsule Tightness

Posterior Capsule Tightness

Dr. GJohn Mullen Blog, Injuries, Latest&Greatest Leave a Comment

Posterior shoulder tightness is common in patients with shoulder injuries. The shoulders are the most commonly injured site in swimmers, suggesting swimmers have tight posterior shoulders. It is believed the posterior capsule is responsible for the tightness in the posterior shoulder, leading to the glenohumeral internal rotational deficit (GIRD) and type 2 superior labrum anterior and posterior (SLAP) lesions, the …

Resistance Exercise Load Does Not Determine Muscle Size

Resistance Exercise Load Does Not Determine Muscle Size

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It is commonly thought the more weight one lifts during resistance training, the greater increase in muscle size (hypertrophy) occurs. Unfortunately, there is minimal evidence suggesting these two conditions correlate. Moreover, the size of a muscle is not suggested to correlate with swimming success. Instead of a percent of maximum, the total volume of weight lifted is potentially a means …

Friday Interview: Dr. Mitch Lomax on Inspiratory Muscle Fatigue (IMF) in Swimming

Friday Interview: Dr. Mitch Lomax on Inspiratory Muscle Fatigue (IMF) in Swimming

Dr. GJohn Mullen Blog, Dr. John Mullen, Latest&Greatest, Training 2 Comments

1. Please introduce yourself to the readers (how you started in the profession, education, credentials, expertise, etc)  I’m a Sport and Exercise Scientist and a Senior Lecturer in Sport and Exercise Physiology at the University of Portsmouth, UK. I gained both my PhD (2007) and MSc (with distinction, 2001) from Brunel University, UK, and my BSc (Hon) from Luton University …