As this shows, a 25 kg load being manually handled is considered to be a safe upper limit for the average man and 16 kg for the average woman. It's important to note, however, that this is only if the person carrying the load can keep it at knuckle height and close to their body.

For the average healthy adult, the "safe" manual handling limit is generally considered to be 20–25 kg (44–55 lbs) for men and 15–20 kg (33–44 lbs) for women when lifting at waist height. In a professional or workplace setting, safety organizations like the HSE (UK) or OSHA (US) suggest these limits to prevent long-term musculoskeletal injuries, particularly to the lower back and intervertebral discs. However, a person's ability to carry weight depends heavily on their core strength, technique, and the "load's center of gravity." When carrying a backpack, a fit person can typically manage 20% to 25% of their body weight for extended periods (e.g., a 70 kg person carrying 14–17 kg). Professional athletes or trained military personnel can carry much more—often up to 50% of their body weight—but this requires specialized training and equipment. To avoid injury, always use your legs to lift, keep the load close to your body, and avoid "twisting" while carrying heavy objects.