{"id":4963,"date":"2025-07-05T12:27:35","date_gmt":"2025-07-05T11:27:35","guid":{"rendered":"https:\/\/pcool.dyndns.org\/?page_id=4963"},"modified":"2025-07-05T23:28:11","modified_gmt":"2025-07-05T22:28:11","slug":"how-squirrels-walk-down-trees","status":"publish","type":"page","link":"https:\/\/pcool.dyndns.org\/index.php\/how-squirrels-walk-down-trees\/","title":{"rendered":"Squirrels Walking Down Trees"},"content":{"rendered":"\n

Paul Cool – 1999<\/p>\n\n\n\n

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Squirrels <\/h2>\n\n\n\n

order: Rodentia
family: Sciuridae
50 genera
260 species<\/p>\n\n\n\n

flying squirrels<\/p>\n\n\n\n

all except gliders: diurnal<\/p>\n<\/div>\n\n\n\n

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Red Squirrel(Sciurus vulgaris<\/em>) Woodland Trust<\/a><\/p>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n

Squirrels and other animals with claws can run up trees.<\/p>\n\n\n\n

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Most animals, like cats and bears, can only come down a tree bottom first.<\/p>\n<\/div>\n<\/div>\n\n\n\n

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Squirrels however, can walk down a tree head first. As can be seen in these images, squirrels can twist their feet and hang from their hind feet.<\/p>\n\n\n\n

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Why is this? Anatomical information available on the internet provides little explanation. Do squirrels have a ball and socket ankle joint? Or is there another explanation? To investigate a road kill found on the road was examined.<\/p>\n\n\n\n

No animals were harmed<\/p>\n<\/div>\n\n\n\n

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Normal<\/p>\n<\/div>\n\n\n\n

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Dorsiflexion<\/p>\n<\/div>\n<\/div>\n\n\n\n

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Plantarflexion<\/p>\n<\/div>\n\n\n\n

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Supination<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n

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3D reconstruction CT scans show a stable ankle joint, but significant motion in the subtalar joint.<\/p>\n<\/div>\n\n\n\n

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Thanks to Dr Victor Cassar-Pullicino and the imaging department at the RJAH orthopaedic hospital.<\/p>\n\n\n\n

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Dissection shows a stable ankle joint with a groove; not<\/strong> a ball and socket joint.<\/p>\n<\/div>\n\n\n\n

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Bone dissection<\/p>\n\n\n\n

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Talus (left) and Calcaneus (right). The needle shows the orientation of the talar facet, allowing excessive subtalar motion.<\/p>\n<\/div>\n<\/div>\n\n\n\n

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Subtalar motion; left neutral position, right inverted.<\/p>\n\n\n\n

Thanks to Andrew Biggs; RJAH photography, for taking the photographs<\/p>\n\n\n\n

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Practice<\/p>\n<\/div>\n\n\n\n

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