Fiber ArchitectureStruktur serat Fusiform parallel Serat otot bergerak

Fiber Architecture(Struktur serat) Fusiform (parallel) • Serat otot bergerak secara longitudinal • Umumnya serat otot tidak merentang sepanjang otot. (generally fibers do not extend the entire length of muscle)

Fiber Architecture Pennate Serat bergerak diagonal terhadap urat daging (fibers run diagonal to the tendon (short fibers))

Fusiform vs. Pennate • fusiform – Keuntungan: sarcomeres berada dalam rangkian jadi kecepatan maksimal dan ROM meningkat. – Kerugian: termasuk rendah # dari parallel sarcomeres jadi tenaga rendah • pennate – Keuntungan : meningkatkan # dari sarcomeres ke parallel, sehingga PCSA dan tenaga meningkat – Kerugian : mengurangi ROM and penurunan kecepatan

Pennation Angles Muscle gastrocnemius Pennation Angle (deg) 10 -25 soleus 15 -30 tibialis anterior 5 -10 biceps femoris 0 Catatan : sudut pennation mungkin meningkat seiring dengan peningkatan tegangan otot. (These pennation angles may increase as the muscle tension increases. ) From: Multiple Muscle Systems, Winters and Woo

Fiber Type Comparison Type I slow Type IIa fast Type IIb fast glycolytic small low oxidative, glycolytic large high medium low medium high Shortening Speed Energy System oxidative Size Force per unit of mass Aerobic Capacity Anaerobic Capacity Fatigability) large high Perhatikan bahwa serat tipe I adalah yang terkecil, karena mengacu pada prinsip ukuran, mereka diterima pertama kali. (Note that type I fibers are smallest therefore, according to the size principle, they are recruited first).

Fiber Types (Jenis Serat) • Semua serat dalam sebuah unit motor adalah jenis yang sama. (all fibers within a motor unit are of the same type) • Dalam sebuah otot ada dari gabungan jenis serat. (within a muscle there is a mixture of fiber types) • Jenis serat mungkin berubah dengan latihan. • Penerimaan yang diatur (recruitment is ordered) – type I serat diterima pertama (awal terkecil, sentakan neuron rendah) fibers recruited 1 st (lowest threshold, slow twitch neurons) – type IIa serat diterima kedua (awal medium, sentakan perlawanan neuron lelah cepat) fibers recruited second (medium threshold, fast twitch fatigue resistant neurons) – type IIb serat diterima terakhir (awal tertinggi, sentakan neuron lelah cepat ) fibers recruited last (highest threshold, fast twitch fatigable neurons)

Fiber Type Distribution (Distribusi Jenis Serat) Muscle vastus medialis Fiber Type (%SO, %FOG, %FG) 50, 15, 35 erector spinae 58, - , 42 soleus 80, - , 20 orbicularis oculi 15, - , 85 From: Multiple Muscle Systems, Winters and Woo

Twitch Force and Fatigue (Tenaga dan Kelelahan) MU 1 (type IIb) MU 2 (type IIa) MU 3 (type I) Tetanic Force Time (short duration) MU 1 MU 2 MU 3 Time (long duration)

Force – Velocity Relationship (Hubungan tenaga-tegangan) force v<0 (eccentric) v=0 (isometric) Catatan: Diperuntukkan bagi kontraksi maksimum pada jarak relaksasi otot. (This is for a maximal contraction at the resting length of the muscle). v>0 (concentric) velocity of contraction (kecepatan kontraksi)

Hubungan Kekuatan-Kecepatan (Power – Velocity Relationship) F Power (F*v) 30% vmax v

long fibers short fibers Muscle Velocity (cm/s) Force (N) Struktur dan Kekuatan/Kecepatan (Architecture and Force/Velocity) large PCSA small PCSA Muscle Velocity (cm/s)

Active Length-Tension L 0= jarak relaksasi(tidak berkontraksi maupun merentang) resting length (neither contracted nor stretched) T e n s i o n Length L 0

Panjang-Tegangan (Length-Tension) Catatan: Diperuntukkan bagi kontraksi isometerik maksimum. T e n s i o n physiological range active Length L 0 combined passive

Struktur dan Panjang/Tegangan (Architecture and Length/Tension) large PCSA short fibers Muscle Length (cm) Force (N) long fibers small PCSA Muscle Length (cm)

Jumlah sendi yang dilewati. (Number of Joints Crossed) uniarticular or monoarticular – otot melintasi tulang sendi, jadi mempengaruhi gerakan hanya pada 1 tulang sendi. (the muscle crosses 1 joint, so it affects motion at only 1 joint) biarticular and multiarticular (multijoint) – otot melintasi 2 atau lebih sendi, menghasilkan gerakan melintasi banyak sendi. (the muscle crosses 2 (bi) or more (multi) joints, so it can produce motion across multiple joints)