Related Experiment Video

Updated: Jun 9, 2026

Myo-mechanical Analysis of Isolated Skeletal Muscle
08:42

Myo-mechanical Analysis of Isolated Skeletal Muscle

Published on: February 22, 2011

Mechanisms of skeletal muscle weakness

Håkan Westerblad1, Nicolas Place, Takashi Yamada

  • 1Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden. Hakan.Westerblad@ki.se

Advances in Experimental Medicine and Biology
|September 9, 2010
PubMed

Insights

Skeletal muscle weakness stems from intrinsic cellular defects affecting muscle cells. Research using mouse models reveals how issues in calcium release or cross-bridge function impair muscle force production.

Area of Science:

  • Muscle physiology
  • Cellular biology
  • Pathology

Background:

  • Skeletal muscle weakness is prevalent in aging and various diseases.
  • It can result from reduced muscle mass or intrinsic muscle cell defects.
  • Understanding cellular mechanisms is key to addressing muscle weakness.

Purpose of the Study:

  • To explore intrinsic cellular mechanisms underlying skeletal muscle weakness.
  • To use mouse disease models to illustrate defects in the activation-contraction pathway.
  • To identify specific cellular sites contributing to decreased force production.

Main Methods:

  • Review of data from mouse disease models.
  • Analysis of the cellular activation-contraction pathway.
  • Examination of calcium handling and myofibrillar function.

Main Results:

  • Defects in calcium release from the sarcoplasmic reticulum cause weakness.
  • Reduced myofibrillar calcium sensitivity impairs force generation.
  • Impaired cross-bridge function limits the ability to produce force.

Conclusions:

  • Intrinsic defects in skeletal muscle cells are significant contributors to muscle weakness.
  • Specific cellular defects, including calcium handling and cross-bridge function, are identified.
  • Mouse models provide valuable insights into human muscle pathologies.

More Related Videos

Measuring Neuromuscular Junction Functionality10:40

Measuring Neuromuscular Junction Functionality

Published on: August 6, 2017

Immunolabelling Myofiber Degeneration in Muscle Biopsies06:37

Immunolabelling Myofiber Degeneration in Muscle Biopsies

Published on: December 5, 2019

Related Concept Videos

Disorders of the Skeletal Muscle01:28

Disorders of the Skeletal Muscle

The clinical conditions affecting the skeletal muscle tissue are broadly categorized as musculoskeletal and neuromuscular disorders.
Musculoskeletal disorders
Musculoskeletal disorders involve injuries and conditions affecting the skeletal muscles and associated connective tissues. These disorders can arise from acute biomechanical stresses or chronic overuse and can occur across different age groups. Common injuries include sprains, fractures, and muscular strains, often resulting from...
Chemical Synapses01:26

Chemical Synapses

Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Chemical Synapses01:26

Chemical Synapses

Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Cross-bridge Cycle01:26

Cross-bridge Cycle

As muscle contracts, the overlap between the thin and thick filaments increases, decreasing the length of the sarcomere—the contractile unit of the muscle—using energy in the form of ATP. At the molecular level, this is a cyclic, multistep process that involves binding and hydrolysis of ATP, and movement of actin by myosin.
Myasthenia Gravis ll: Pathophysiology01:22

Myasthenia Gravis ll: Pathophysiology

The disease process of myasthenia gravis begins at the neuromuscular junction, where antibodies attack key proteins needed for muscle activation. This immune reaction weakens signal transmission, leading to the characteristic muscle fatigue and weakness that define the condition.Immune-Mediated DamageIn most individuals, antibodies target acetylcholine receptors (AChRs) on the postsynaptic membrane of muscle cells. By blocking acetylcholine binding, these antibodies prevent the nerve signal...
Alterations in Muscle Tone lll01:11

Alterations in Muscle Tone lll

Rigidity and myotonia are distinct abnormalities of muscle tone that affect resistance and relaxation during movement. Although both involve altered muscle contraction, they arise from different neurological and muscular mechanisms.CharacteristicsRigidity is characterized by uniform resistance to passive movement across the entire range, independent of speed, affecting flexors and extensors equally. It may appear as lead-pipe rigidity (smooth, constant resistance) or cogwheel rigidity...