Muscle And Tendon Flashcards
what are the tissues involved with the musculotendon unit?
-ligaments (bone to bone)
-tendon (muscle to bone)
*It is important to view these structures together. They work as a unit and are woven together sort of like ropes
What area of muscle/tendon are prone to injury?
Junction areas (muscle tendon/ tendon bone)
Muscle tone
The tension of a muscle while it is at rest. Without the tone, the muscle can’t keep joints together. (Ex. Shoulder)
How is a muscle arranged
Myofilaments, myofibrils, muscle fibers, fascicles, muscle
Characteristics of a tendon
-crimp at rest, when muscle is contracted they are parallel
-resists tensions
-does not handle twisting or compression (why we have sesamoids/bursae)
The contractile unit of muscle
-Sarcomeres: multiple bands that allow tension generation via sliding or cross bridge formation
-ATP/ADP use for function
-they lie between z-disks
-they are added or deleted with immobility or lack of drive (when a person is flexed for too long, muscle starts to delete)
-Sarcomerogenesis
Which type of movement can we generate the most muscle tension
Eccentric movement
Titin
Functions as a molecular spring that is responsible for passive elasticity in the muscle cell
Isometric
Muscle contraction where the filaments generate tension but the units do not move
Concentric
Muscle contraction where the muscle units generate enough tension that the muscle unit pulls together
Eccentric
Muscle contraction where there is tension, but the muscle unit is moving farther apart (most tension can occur here than concentric)
Muscle contusion
-disruption of tissue
-bleeding (the bleeding is what usually causes pain, due to the large inflammatory response)
-regeneration is usually not a factor
Muscle strain
-Stretching or tearing of a muscle or tendon
-muscle tendon junction (most commonly the distal MTJ last sarcomere or two)
-associated with eccentric activation (heavy loads)
What often causes DOMS
Related to eccentric activation in naive subjects (peaks 48-72 hours)
Tendon- injury/pathology
-Macrotrauma: a single event, you know you have done it, often an itis-inflamed
-Microtrauma: part of repetitive cycles-submaximal, often leading to digerati events processes (osis-degeneration) “it hurts when…”
-can be tendon sheath related (inflammation)
Tendonitis
-Macrotrauma and inflammatory
-single event
-extrinsic overload
-macroscopic injury
-significant event
-Acute: less than 2 weeks
-Subacute: 2-6 weeks
-Chronic: 6 or more weeks
Tendonosis (tendinopathy)
-microtraumatic and degenerative
-Repetitive action
-intrinsic trauma
-often eccentric demand
-stabilizing/absorbing
-focal area of intratendinous degeneration that is initially asymptomatic and may remain unless a specific stress is brought forth
*may be related to aging and significant use (accumulative microtrauma) -> amount of elastic in tissue decreases causing them to become more rigid
Tenosynovitis
-inflammation of paratendon “sheath restriction”
-abuse (overuse) or septic (infection)
Tendon structure
-macroscopic appearance: crimp at rest, longitudinal orientation
-microscopic appearance: tightly arranged parallel fibers organized sequence of structures
-tropocollagen, microfibrils, subfibril, fibril, fascicle, tendon
Recruitment and fiber types
-Slow Oxidative (SO): always first, smaller nerve fibers, fewer/smaller MU recruited
-Fast oxidative glycolytic: Next fibers to be recruited, intermediate
-Fast glycolytic: Least fatigue resistant
*Ideally you have a training program that trains the system you use the most
Impact of shape and structure of muscle fibers
-muscle fiber orientation directly impacts tension generation capacity (the higher the number of fibers in cross section the greater tension generation capacity)
-if not perpendicular, less generating capacity
Impact of training on muscular strength
-neural comes first (neurological response)
-muscular strength next (6-8 weeks) (muscle changes)
-tendon strength last (10-12 weeks) (tendon response)
Length tension ratio
-optimal length tension ration is where best cross bridge formation occurs
-in rehab, you can use a quick stretch and different portions of the ROM
Force velocity rules
-concentric: as you increase speed, you decrease force/torque output
-eccentric: as you increase speed, you increase/keep constant force/torque output
What is flexibility
-connective tissue is the limiting factor (perimysium and endomysium)
-ROM through which the joint can move
-Stretching will only increase flexibility if it is constantly worked (otherwise it will be reversed)
-Increase in flexibility does not necessarily result in a decrease in injuries (previous injury is the best way to predict a future injury)
Muscle Strain
-Usually multi joint muscles (inarticulate)
-eccentric load to an activated muscle
-injury is at MTJ (usually distal)
-Reaction is inflammatory
Strain Levels
-Mild: 1st, few fibers, limited response, no loss of strength in MTU, moderate pain
-moderate: 2nd, larger number of fibers, significant inflammatory response, many weeks, loss of muscle strength in MTU, but intact
-Avulsion: 3rd, complete disruption, often from insertion rather than muscle from tendon, may be surgical
How do we treat contusions
-benign neglect
-donut pad if area that may receive impact (load around it not on it)
-often looks worse as it moves to the surface (looks do not correlate to severity)
-self limiting/ed unless underlying contribution (ex. Clotting disorder)
how do we treat strains
-recognize limiting factors: pain from inflammation, decreased MT output or decreased strength early post injury
-may use modalities to increase blood flow after initial phase
-NSAID’s from MD 2-3 days - PRICE initial care
-no aggressive stretching- progressive strengthening (eccentric works well) (slow and heavy)
-Progressive function
Good exercises for hamstrings
-Nordic hamstrings
-hip hinges
How do we treat tenosynovitis
-remember it is usually a result of repetitive overuse (repetitive wrist/thumb action)
-put it at rest: sometimes just leave it alone
-NSAIDs from MD (3-5 days)
-PRICE: rest it at night in splint if needed, if really uncomfortable can use iontophoresis
