Week5

Tendons and ligaments

1st metatarsal is shorter and thicker than other metatarsals. This is because most weight during push off goes through first metatarsal.

“Hallux rigidus” prevents 1st MTP mobility. If 1st met loads are displaced onto 5th metatarsal, risk of stress fracture increases.

Plantar fascia attatches calcaneus through 1st MTP.

As 1st MTP

Why do we want “rigid” arch as opposed to elastic arch?

Collagen makes up 25-35% of proteins in humans

types (list all types of collagen)

Collagen makes up ~70-80% of dry weight in tendons.

Type I collagen makes up 65-80% of total collagen in tendons.

tendon structure: fibril - fiber - {primary fiber bundle - secondary fiber bundle} “fascicle” - tertiary fiber bundle (blood vessels and nerves begin here) -

Higher proteoglycan content is found in tendons which experience more compression

Ligaments vs. Tendons both contain: collagen fibrils (type I), proteoglycan matrix, fibroblasts arranged in parallel rows.

graph LR
    A(collagen) --> B(microfibril);
    B --> C(fibril);
    C --> D(fiber);
    D --> E(fasicle);

Feb 14

Optimal tendon and ligament functoin occurs around 5-7% of resting length (could be more?)

tendons can return majority of stored energy (approx. 90%)

how does https://doi.org/10.1093/ptj/77.10.1090 affect stretching?

https://bbrc.in/bbrc/2018July-Sep-Vol11-3-pdf/BBRC20_023.pdf

https://pmc.ncbi.nlm.nih.gov/articles/PMC10124737/ - 60 min per day