结论：护理者的负担是可测量的，而测量之后才能改进
轮椅和护理设备的操作，很多由护理者完成——推行、折叠、搬运、调节、转移协助。
这些操作的力量需求如果过大，带来两方面的问题：
照护质量。 操作费力可能导致护理者简化或省略某些步骤，比如不调节到位、不做检查。
职业健康。 长期的高强度操作是护理人员腰背损伤的重要原因，而这在护理行业中是普遍问题。
操作力是可以测量的物理量，测出来之后才能与可接受范围比较，也才能评价改进的效果。
涉及的主要操作
| 操作 | 力的类型 |
|---|---|
| 平地推行 | 持续推力 |
| 上下坡推行 | 较大的持续力 |
| 越障（门槛、台阶） | 瞬时较大力，含抬起 |
| 转向 | 侧向力与力矩 |
| 制动与控制 | 制动时的拉力 |
| 折叠展开 | 操作力，可能是不便姿势 |
| 搬运（上下车） | 抬举力，整机重量 |
| 调节（座高、靠背角度） | 操作力与保持力 |
| 转移协助 | 支撑与移动使用者的力 |
「搬运」和「越障」是力量需求较大的两类操作，也是腰背损伤的主要来源。
测量的方法
推行力的测量。 在规定的路面、坡度、载重下，测量维持匀速推行所需的力。
起始力与维持力。 起动时的力大于维持时的力，两者都要测。
越障力。 通过规定高度障碍所需的力和方式。
折叠操作力。 完成折叠动作各步骤所需的力。
抬举重量。 整机及各部件的重量。
调节操作力。 各调节机构的操作力。
测量条件的记录。 载重、路面、坡度、温度，这些都影响结果。
「起始力」容易被忽略，但它往往是最大的——静止的轮椅起动时要克服静摩擦和惯性，这个瞬间的力可能明显高于匀速推行时。
影响操作力的因素
整机重量。 直接影响推行力和搬运负担。
转动阻力。 轴承、轮胎的阻力。
轮径。 大轮越障更容易，滚动阻力也不同。
轮胎。 气压、材质、胎面。
路面。 地毯、粗糙地面阻力明显增大。
载重。 使用者体重。
推手高度。 不合适的高度增加护理者的负担。
转动部件的维护状态。 缺乏润滑或有磨损时阻力增大。
「推手高度」是人机工程上的关键参数。 高度不合适会迫使护理者弯腰或者抬臂，长期如此是腰背和肩部损伤的原因。可调推手高度是有价值的设计。
可接受范围的判断
参照人体能力数据。 不同性别、年龄的力量能力有统计数据可参考。
考虑持续时间。 短时的大力与长时间的中等力，负担不同。
考虑频次。 一天要做多少次这个操作。
考虑姿势。 不良姿势下的力量能力明显下降。
考虑使用人群。 护理者中女性和年长者比例可能较高。
「考虑姿势」很重要。 同样的力，站直了推与弯腰抬，对腰背的负担完全不同。评价时应当考虑操作时的实际姿势。
设计上的改进方向
减轻重量。 直接降低搬运负担。前面专门讲过轻量化的验证。
降低转动阻力。 优化轴承、轮胎选择。
优化推手设计。 高度可调、角度合适、握持舒适。
改善越障能力。 轮径、前轮设计、辅助越障机构。
简化折叠操作。 减少步骤、降低所需力量。
增加助力。 电动助力推行装置。
改善调节机构。 降低调节所需的力，便于操作的位置。
拆分搬运。 可拆卸设计，降低单次搬运的重量。
「可拆卸设计」对搬运负担的改善明显。 整机二十多公斤一次搬运，与拆成几部分分次搬运，对护理者腰背的负担差别很大。
资料中应当说明的
整机与各部件重量。 便于判断搬运负担。
推行所需的力（典型条件下）。 便于比较。
推荐的操作方式。 正确的姿势和方法。
折叠与搬运的步骤。 图示化说明。
推手高度的调节范围。
需要几人操作的情形。 哪些操作不应当单人完成。
「需要几人操作」要明确，因为护理现场人手紧张时，本该两人的操作可能一人做，这是受伤的常见场景。
与使用者能力的配合
除了护理者，使用者自身的操作能力也要考虑：
自主驱动的力量需求。 手动轮椅使用者推动轮圈所需的力。
制动操作。 使用者操作驻车制动所需的力和手部功能。
调节操作。 使用者能否自己调节座椅、脚踏。
转移动作。 上下轮椅所需的能力。
折叠。 使用者能否自己折叠。
「制动操作力」对上肢力量有限的使用者是实际问题。 制动杆的位置、长度、所需力量决定了使用者能否自主制动，而不能自主制动意味着失去了独立性。
数据的应用
操作力数据可以用在：产品选型的依据（护理者或使用者能否操作）；设计改进的方向；产品比较的维度；以及职业健康评估的输入。
「职业健康评估的输入」对机构客户有价值，因为机构需要评估设备对护理人员的负担。
测量条件的统一
操作力的数据要有可比性，条件必须统一并记录：
载重。 模拟使用者的重量与分布。
路面。 材质、摩擦系数、平整度。
坡度。 平地还是规定坡度。
轮胎状态。 气压、磨损程度。
速度。 推行的速度。
环境温度。 影响润滑和轮胎。
「轮胎气压」对推行力的影响很明显，气压不足时滚动阻力明显增加，测量前应当校准到规定值并记录。
我们的做法
做轮椅检测时，推行力和操作力可以作为性能项目测量，测量时我们会完整记录条件 ——载重、路面、坡度、轮胎气压，因为这些因素对结果影响很大，条件不记录数据就无法比较。
对于以「省力」「易搬运」为卖点的产品，我们建议把操作力和重量作为明确的性能参数测量并在资料中给出，具体数值比「轻便易推」这样的描述对采购方和护理者更有参考价值。
如果你有产品需要做操作力相关的测量，可以把产品和关注的操作场景发过来一起确定测试方案，或者直接联系：132 4819 8029。检测能力见服务介绍，产品分类见手动轮椅检测与电动轮椅检测，案例见案例。
English version
Conclusion. Many operations on wheelchairs and care equipment are performed by carers: pushing, folding, lifting, adjusting and assisting transfers. Where those operations demand excessive force, two problems follow. Care quality suffers, since effortful operations lead carers to simplify or skip steps, such as not adjusting fully or not checking. And occupational health suffers, since sustained heavy operation is a significant cause of back injury among care staff, a widespread problem in the sector. Operating force is a measurable physical quantity, and only once measured can it be compared against acceptable ranges and improvements evaluated.
Operations involved. Pushing on the level requires sustained push force. Pushing on slopes requires greater sustained force. Negotiating obstacles such as thresholds and steps requires momentary higher force including lifting. Steering requires lateral force and moment. Braking and control require pulling force. Folding and unfolding require operating force, often in awkward postures. Lifting into and out of vehicles requires lifting the whole product's weight. Adjustment of seat height and backrest angle requires operating and holding force. And transfer assistance requires supporting and moving the user. Lifting and obstacle negotiation demand the greatest force and are the principal sources of back injury.
Measurement methods. Push force is measured on a specified surface, gradient and load as the force needed to maintain steady speed. Starting and sustaining forces differ, with starting the higher, and both should be measured. Obstacle force covers the force and technique needed to cross an obstacle of specified height. Folding force covers each step of the folding operation. Lifting weight covers the whole product and its components. Adjustment force covers each adjustment mechanism. And conditions must be recorded, covering load, surface, gradient and temperature, all of which affect results. Starting force is easily overlooked while often being the greatest: starting a stationary chair requires overcoming static friction and inertia, and that momentary force can markedly exceed the force needed to keep moving.
Factors affecting operating force. Whole product weight affects both push force and lifting burden. Rolling resistance from bearings and tyres. Wheel diameter, since larger wheels negotiate obstacles more easily and roll differently. Tyres, in pressure, material and tread. Surface, since carpet and rough ground markedly increase resistance. Load, meaning the user's weight. Push handle height, since an unsuitable height increases the carer's burden. And the maintenance condition of rotating parts, since inadequate lubrication or wear increases resistance. Push handle height is a key ergonomic parameter: an unsuitable height forces the carer to stoop or raise the arms, which over time causes back and shoulder injury. Adjustable push handle height is a worthwhile design feature.
Judging acceptable ranges. Refer to human capability data, for which statistics exist by sex and age. Consider duration, since brief high force and sustained moderate force impose different burdens. Consider frequency, meaning how often the operation is performed daily. Consider posture, since capability falls markedly in poor postures. And consider the population, since carers may include a high proportion of women and older workers. Posture matters greatly: the same force applied standing upright and applied stooping imposes entirely different loads on the back, and assessment should reflect the actual working posture.
Design improvements. Reducing weight lowers lifting burden directly, with lightweighting verification discussed separately. Reducing rolling resistance through bearing and tyre selection. Optimising push handle design in adjustable height, suitable angle and comfortable grip. Improving obstacle negotiation through wheel diameter, castor design and assist mechanisms. Simplifying folding by reducing steps and force. Adding power assist for pushing. Improving adjustment mechanisms with lower force and accessible positions. And enabling separation for lifting through detachable design. Detachable design improves the lifting burden noticeably: lifting twenty-odd kilograms in one go differs greatly, for the carer's back, from lifting several lighter parts separately.
What the documentation should state. Whole product and component weights, to inform judgements about lifting. Push force under typical conditions, to allow comparison. Recommended operating technique covering correct posture and method. Folding and lifting steps, illustrated. Push handle height adjustment range. And which operations require more than one person. State the number of operators clearly: where staffing is tight, an operation intended for two may be done by one, which is a common injury scenario.
How we handle it. In wheelchair testing, push force and operating forces can be measured as performance items, and we record the conditions in full, covering load, surface, gradient and tyre pressure, since those strongly affect results and unrecorded conditions make data incomparable. For products sold on ease of pushing or portability we suggest measuring operating force and weight as explicit performance parameters and stating them in the documentation: specific figures are more useful to purchasers and carers than a description such as light and easy to push.
Send us the product and the operations of concern and we will define the test approach. Phone or WeChat: +86 132 4819 8029.